1 /*
2 * Copyright (c) 2018, 2026, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "cds/aotArtifactFinder.hpp"
26 #include "cds/aotCacheAccess.hpp"
27 #include "cds/aotClassInitializer.hpp"
28 #include "cds/aotClassLocation.hpp"
29 #include "cds/aotCompressedPointers.hpp"
30 #include "cds/aotConstantPoolResolver.hpp"
31 #include "cds/aotLogging.hpp"
32 #include "cds/aotMappedHeapLoader.hpp"
33 #include "cds/aotMappedHeapWriter.hpp"
34 #include "cds/aotMetaspace.hpp"
35 #include "cds/aotOopChecker.hpp"
36 #include "cds/aotReferenceObjSupport.hpp"
37 #include "cds/aotStreamedHeapLoader.hpp"
38 #include "cds/aotStreamedHeapWriter.hpp"
39 #include "cds/archiveBuilder.hpp"
40 #include "cds/archiveUtils.hpp"
41 #include "cds/cds_globals.hpp"
42 #include "cds/cdsConfig.hpp"
43 #include "cds/cdsEnumKlass.hpp"
44 #include "cds/cdsHeapVerifier.hpp"
45 #include "cds/heapShared.inline.hpp"
46 #include "cds/regeneratedClasses.hpp"
47 #include "classfile/classLoaderData.hpp"
48 #include "classfile/javaClasses.inline.hpp"
49 #include "classfile/modules.hpp"
50 #include "classfile/stringTable.hpp"
51 #include "classfile/symbolTable.hpp"
52 #include "classfile/systemDictionary.hpp"
53 #include "classfile/systemDictionaryShared.hpp"
54 #include "classfile/vmClasses.hpp"
55 #include "classfile/vmSymbols.hpp"
56 #include "code/aotCodeCache.hpp"
57 #include "gc/shared/collectedHeap.hpp"
58 #include "gc/shared/gcLocker.hpp"
59 #include "gc/shared/gcVMOperations.hpp"
60 #include "logging/log.hpp"
61 #include "logging/logStream.hpp"
62 #include "memory/iterator.inline.hpp"
63 #include "memory/resourceArea.hpp"
64 #include "memory/universe.hpp"
65 #include "oops/compressedOops.inline.hpp"
66 #include "oops/fieldStreams.inline.hpp"
67 #include "oops/objArrayOop.inline.hpp"
68 #include "oops/oop.inline.hpp"
69 #include "oops/oopHandle.inline.hpp"
70 #include "oops/typeArrayOop.inline.hpp"
71 #include "prims/jvmtiExport.hpp"
72 #include "runtime/arguments.hpp"
73 #include "runtime/fieldDescriptor.inline.hpp"
74 #include "runtime/globals_extension.hpp"
75 #include "runtime/init.hpp"
76 #include "runtime/javaCalls.hpp"
77 #include "runtime/mutexLocker.hpp"
78 #include "runtime/safepointVerifiers.hpp"
79 #include "utilities/bitMap.inline.hpp"
80 #include "utilities/copy.hpp"
81 #if INCLUDE_G1GC
82 #include "gc/g1/g1CollectedHeap.hpp"
83 #endif
84
85 #if INCLUDE_CDS_JAVA_HEAP
86
87 struct ArchivableStaticFieldInfo {
88 const char* klass_name;
89 const char* field_name;
90 InstanceKlass* klass;
91 int offset;
92 BasicType type;
93
94 ArchivableStaticFieldInfo(const char* k, const char* f)
95 : klass_name(k), field_name(f), klass(nullptr), offset(0), type(T_ILLEGAL) {}
96
97 bool valid() {
98 return klass_name != nullptr;
99 }
100 };
101
102 HeapArchiveMode HeapShared::_heap_load_mode = HeapArchiveMode::_uninitialized;
103 HeapArchiveMode HeapShared::_heap_write_mode = HeapArchiveMode::_uninitialized;
104
105 size_t HeapShared::_alloc_count[HeapShared::ALLOC_STAT_SLOTS];
106 size_t HeapShared::_alloc_size[HeapShared::ALLOC_STAT_SLOTS];
107 size_t HeapShared::_total_obj_count;
108 size_t HeapShared::_total_obj_size;
109
110 #ifndef PRODUCT
111 #define ARCHIVE_TEST_FIELD_NAME "archivedObjects"
112 static Array<char>* _archived_ArchiveHeapTestClass = nullptr;
113 static const char* _test_class_name = nullptr;
114 static Klass* _test_class = nullptr;
115 static const ArchivedKlassSubGraphInfoRecord* _test_class_record = nullptr;
116 #endif
117
118
119 //
120 // If you add new entries to the following tables, you should know what you're doing!
121 //
122
123 static ArchivableStaticFieldInfo archive_subgraph_entry_fields[] = {
124 {"java/lang/Integer$IntegerCache", "archivedCache"},
125 {"java/lang/Long$LongCache", "archivedCache"},
126 {"java/lang/Byte$ByteCache", "archivedCache"},
127 {"java/lang/Short$ShortCache", "archivedCache"},
128 {"java/lang/Character$CharacterCache", "archivedCache"},
129 {"java/util/jar/Attributes$Name", "KNOWN_NAMES"},
130 {"sun/util/locale/BaseLocale", "constantBaseLocales"},
131 {"jdk/internal/module/ArchivedModuleGraph", "archivedModuleGraph"},
132 {"java/util/ImmutableCollections", "archivedObjects"},
133 {"java/lang/ModuleLayer", "EMPTY_LAYER"},
134 {"java/lang/module/Configuration", "EMPTY_CONFIGURATION"},
135 {"jdk/internal/math/FDBigInteger", "archivedCaches"},
136 {"java/lang/reflect/Proxy$ProxyBuilder", "archivedData"}, // FIXME -- requires AOTClassLinking
137
138 #ifndef PRODUCT
139 {nullptr, nullptr}, // Extra slot for -XX:ArchiveHeapTestClass
140 #endif
141 {nullptr, nullptr},
142 };
143
144 // full module graph
145 static ArchivableStaticFieldInfo fmg_archive_subgraph_entry_fields[] = {
146 {"jdk/internal/loader/ArchivedClassLoaders", "archivedClassLoaders"},
147 {ARCHIVED_BOOT_LAYER_CLASS, ARCHIVED_BOOT_LAYER_FIELD},
148 {"java/lang/Module$ArchivedData", "archivedData"},
149 {nullptr, nullptr},
150 };
151
152 KlassSubGraphInfo* HeapShared::_dump_time_special_subgraph;
153 ArchivedKlassSubGraphInfoRecord* HeapShared::_run_time_special_subgraph;
154 GrowableArrayCHeap<oop, mtClassShared>* HeapShared::_pending_roots = nullptr;
155 OopHandle HeapShared::_scratch_basic_type_mirrors[T_VOID+1];
156 MetaspaceObjToOopHandleTable* HeapShared::_scratch_objects_table = nullptr;
157
158 static bool is_subgraph_root_class_of(ArchivableStaticFieldInfo fields[], InstanceKlass* ik) {
159 for (int i = 0; fields[i].valid(); i++) {
160 if (fields[i].klass == ik) {
161 return true;
162 }
163 }
164 return false;
165 }
166
167 bool HeapShared::is_subgraph_root_class(InstanceKlass* ik) {
168 assert(CDSConfig::is_dumping_heap(), "dump-time only");
169 if (CDSConfig::is_dumping_klass_subgraphs()) {
170 // Legacy CDS archive support (to be deprecated)
171 return is_subgraph_root_class_of(archive_subgraph_entry_fields, ik) ||
172 is_subgraph_root_class_of(fmg_archive_subgraph_entry_fields, ik);
173 } else {
174 return false;
175 }
176 }
177
178 oop HeapShared::CachedOopInfo::orig_referrer() const {
179 return _orig_referrer.resolve();
180 }
181
182 // This is a simple hashing of the oop's address. This function is used
183 // while copying the oops into the AOT heap region. We don't want to
184 // have any side effects during the copying, so we avoid calling
185 // p->identity_hash() which can update the object header.
186 unsigned HeapShared::oop_address_hash(oop const& p) {
187 assert(SafepointSynchronize::is_at_safepoint() ||
188 JavaThread::current()->is_in_no_safepoint_scope(), "sanity");
189 return primitive_hash(cast_from_oop<intptr_t>(p));
190 }
191
192 // About the hashcode in the cached objects:
193 // - If a source object has a hashcode, it must be copied into the cache.
194 // That's because some cached hashtables are laid out using this hashcode.
195 // - If a source object doesn't have a hashcode, we avoid computing it while
196 // copying the objects into the cache. This will allow the hashcode to be
197 // dynamically and randomly computed in each production, which generally
198 // desirable to make the hashcodes more random between runs.
199 unsigned HeapShared::archived_object_cache_hash(OopHandle const& oh) {
200 oop o = oh.resolve();
201 if (o == nullptr) {
202 return 0;
203 }
204 if (!_use_identity_hash_for_archived_object_cache) {
205 // This is called while we are copying the objects. Don't call o->identity_hash()
206 // as that will update the object header.
207 return oop_address_hash(o);
208 } else {
209 // This is called after all objects are copied. It's OK to update
210 // the object's hashcode.
211 //
212 // This may be called after we have left the AOT dumping safepoint.
213 // Objects in archived_object_cache() may be moved by the GC, so we
214 // can't use the address of o for computing the hash.
215 return o->identity_hash();
216 }
217 }
218
219 bool HeapShared::oop_handle_equals(const OopHandle& a, const OopHandle& b) {
220 return a.resolve() == b.resolve();
221 }
222
223 static void reset_states(oop obj, TRAPS) {
224 Handle h_obj(THREAD, obj);
225 InstanceKlass* klass = InstanceKlass::cast(obj->klass());
226 TempNewSymbol method_name = SymbolTable::new_symbol("resetArchivedStates");
227 Symbol* method_sig = vmSymbols::void_method_signature();
228
229 while (klass != nullptr) {
230 Method* method = klass->find_method(method_name, method_sig);
231 if (method != nullptr) {
232 assert(method->is_private(), "must be");
233 if (log_is_enabled(Debug, aot)) {
234 ResourceMark rm(THREAD);
235 log_debug(aot)(" calling %s", method->name_and_sig_as_C_string());
236 }
237 JavaValue result(T_VOID);
238 JavaCalls::call_special(&result, h_obj, klass,
239 method_name, method_sig, CHECK);
240 }
241 klass = klass->super();
242 }
243 }
244
245 void HeapShared::reset_archived_object_states(TRAPS) {
246 assert(CDSConfig::is_dumping_heap(), "dump-time only");
247 log_debug(aot)("Resetting platform loader");
248 reset_states(SystemDictionary::java_platform_loader(), CHECK);
249 log_debug(aot)("Resetting system loader");
250 reset_states(SystemDictionary::java_system_loader(), CHECK);
251
252 // Clean up jdk.internal.loader.ClassLoaders::bootLoader(), which is not
253 // directly used for class loading, but rather is used by the core library
254 // to keep track of resources, etc, loaded by the null class loader.
255 //
256 // Note, this object is non-null, and is not the same as
257 // ClassLoaderData::the_null_class_loader_data()->class_loader(),
258 // which is null.
259 log_debug(aot)("Resetting boot loader");
260 JavaValue result(T_OBJECT);
261 JavaCalls::call_static(&result,
262 vmClasses::jdk_internal_loader_ClassLoaders_klass(),
263 vmSymbols::bootLoader_name(),
264 vmSymbols::void_BuiltinClassLoader_signature(),
265 CHECK);
266 Handle boot_loader(THREAD, result.get_oop());
267 reset_states(boot_loader(), CHECK);
268 }
269
270 void HeapShared::ensure_determinism(TRAPS) {
271 TempNewSymbol class_name = SymbolTable::new_symbol("jdk/internal/util/WeakReferenceKey");
272 TempNewSymbol method_name = SymbolTable::new_symbol("ensureDeterministicAOTCache");
273
274 Klass* weak_ref_key_class = SystemDictionary::resolve_or_fail(class_name, true, CHECK);
275 precond(weak_ref_key_class != nullptr);
276
277 log_debug(aot)("Calling WeakReferenceKey::ensureDeterministicAOTCache(Object.class)");
278 JavaValue result(T_BOOLEAN);
279 JavaCalls::call_static(&result,
280 weak_ref_key_class,
281 method_name,
282 vmSymbols::void_boolean_signature(),
283 CHECK);
284 assert(result.get_jboolean() == false, "sanity");
285 }
286
287 void HeapShared::prepare_for_archiving(TRAPS) {
288 reset_archived_object_states(CHECK);
289 ensure_determinism(CHECK);
290 }
291
292 HeapShared::ArchivedObjectCache* HeapShared::_archived_object_cache = nullptr;
293
294 // Controls the hashing method for the _archived_object_cache.
295 // Changes from false to true once, after all objects are copied,
296 // inside make_archived_object_cache_gc_safe().
297 // See archived_object_cache_hash() for more details.
298 bool HeapShared::_use_identity_hash_for_archived_object_cache = false;
299
300 bool HeapShared::is_archived_heap_in_use() {
301 if (HeapShared::is_loading()) {
302 if (HeapShared::is_loading_streaming_mode()) {
303 return AOTStreamedHeapLoader::is_in_use();
304 } else {
305 return AOTMappedHeapLoader::is_in_use();
306 }
307 }
308
309 return false;
310 }
311
312 bool HeapShared::can_use_archived_heap() {
313 FileMapInfo* static_mapinfo = FileMapInfo::current_info();
314 if (static_mapinfo == nullptr) {
315 return false;
316 }
317 if (!static_mapinfo->has_heap_region()) {
318 return false;
319 }
320 if (!static_mapinfo->object_streaming_mode() &&
321 !Universe::heap()->can_load_archived_objects() &&
322 !UseG1GC) {
323 // Incompatible object format
324 return false;
325 }
326
327 return true;
328 }
329
330 bool HeapShared::is_too_large_to_archive(size_t size) {
331 if (HeapShared::is_writing_streaming_mode()) {
332 return false;
333 } else {
334 return AOTMappedHeapWriter::is_too_large_to_archive(size);
335 }
336 }
337
338 bool HeapShared::is_too_large_to_archive(oop obj) {
339 if (HeapShared::is_writing_streaming_mode()) {
340 return false;
341 } else {
342 return AOTMappedHeapWriter::is_too_large_to_archive(obj);
343 }
344 }
345
346 bool HeapShared::is_string_too_large_to_archive(oop string) {
347 typeArrayOop value = java_lang_String::value_no_keepalive(string);
348 return is_too_large_to_archive(value);
349 }
350
351 void HeapShared::initialize_loading_mode(HeapArchiveMode mode) {
352 assert(_heap_load_mode == HeapArchiveMode::_uninitialized, "already set?");
353 assert(mode != HeapArchiveMode::_uninitialized, "sanity");
354 _heap_load_mode = mode;
355 };
356
357 void HeapShared::initialize_writing_mode() {
358 assert(!FLAG_IS_ERGO(AOTStreamableObjects), "Should not have been ergonomically set yet");
359
360 if (!CDSConfig::is_dumping_archive()) {
361 // We use FLAG_IS_CMDLINE below because we are specifically looking to warn
362 // a user that explicitly sets the flag on the command line for a JVM that is
363 // not dumping an archive.
364 if (FLAG_IS_CMDLINE(AOTStreamableObjects)) {
365 log_warning(cds)("-XX:%cAOTStreamableObjects was specified, "
366 "AOTStreamableObjects is only used for writing "
367 "the AOT cache.",
368 AOTStreamableObjects ? '+' : '-');
369 }
370 }
371
372 // The below checks use !FLAG_IS_DEFAULT instead of FLAG_IS_CMDLINE
373 // because the one step AOT cache creation transfers the AOTStreamableObjects
374 // flag value from the training JVM to the assembly JVM using an environment
375 // variable that sets the flag as ERGO in the assembly JVM.
376 if (FLAG_IS_DEFAULT(AOTStreamableObjects)) {
377 // By default, the value of AOTStreamableObjects should match !UseCompressedOops.
378 FLAG_SET_DEFAULT(AOTStreamableObjects, !UseCompressedOops);
379 } else if (!AOTStreamableObjects && UseZGC) {
380 // Never write mapped heap with ZGC
381 if (CDSConfig::is_dumping_archive()) {
382 log_warning(cds)("Heap archiving without streaming not supported for -XX:+UseZGC");
383 }
384 FLAG_SET_ERGO(AOTStreamableObjects, true);
385 }
386
387 if (CDSConfig::is_dumping_archive()) {
388 // Select default mode
389 assert(_heap_write_mode == HeapArchiveMode::_uninitialized, "already initialized?");
390 _heap_write_mode = AOTStreamableObjects ? HeapArchiveMode::_streaming : HeapArchiveMode::_mapping;
391 }
392 }
393
394 void HeapShared::initialize_streaming() {
395 assert(is_loading_streaming_mode(), "shouldn't call this");
396 if (can_use_archived_heap()) {
397 AOTStreamedHeapLoader::initialize();
398 }
399 }
400
401 void HeapShared::enable_gc() {
402 if (AOTStreamedHeapLoader::is_in_use()) {
403 AOTStreamedHeapLoader::enable_gc();
404 }
405 }
406
407 void HeapShared::materialize_thread_object() {
408 if (AOTStreamedHeapLoader::is_in_use()) {
409 AOTStreamedHeapLoader::materialize_thread_object();
410 }
411 }
412
413 void HeapShared::archive_interned_string(oop string) {
414 assert(HeapShared::is_writing_mapping_mode(), "Only used by this mode");
415 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, string);
416 assert(success, "shared strings array must not point to arrays or strings that are too large to archive");
417 }
418
419 void HeapShared::finalize_initialization(FileMapInfo* static_mapinfo) {
420 if (HeapShared::is_loading()) {
421 if (HeapShared::is_loading_streaming_mode()) {
422 // Heap initialization can be done only after vtables are initialized by ReadClosure.
423 AOTStreamedHeapLoader::finish_initialization(static_mapinfo);
424 } else {
425 // Finish up archived heap initialization. These must be
426 // done after ReadClosure.
427 AOTMappedHeapLoader::finish_initialization(static_mapinfo);
428 }
429 }
430 }
431
432 void HeapShared::make_archived_object_cache_gc_safe() {
433 ArchivedObjectCache* new_cache = new (mtClass)ArchivedObjectCache(INITIAL_TABLE_SIZE, MAX_TABLE_SIZE);
434
435 // It's safe to change the behavior of the hash function now, because iterate_all()
436 // doesn't call the hash function.
437 // See archived_object_cache_hash() for more details.
438 assert(_use_identity_hash_for_archived_object_cache == false, "happens only once");
439 _use_identity_hash_for_archived_object_cache = true;
440
441 // Copy all CachedOopInfo into a new table using a different hashing algorithm
442 archived_object_cache()->iterate_all([&] (OopHandle oh, CachedOopInfo info) {
443 new_cache->put_when_absent(oh, info);
444 });
445
446 destroy_archived_object_cache();
447 _archived_object_cache = new_cache;
448 }
449
450 HeapShared::CachedOopInfo* HeapShared::get_cached_oop_info(oop obj) {
451 OopHandle oh(Universe::vm_global(), obj);
452 CachedOopInfo* result = _archived_object_cache->get(oh);
453 oh.release(Universe::vm_global());
454 return result;
455 }
456
457 bool HeapShared::has_been_archived(oop obj) {
458 assert(CDSConfig::is_dumping_heap(), "dump-time only");
459 return get_cached_oop_info(obj) != nullptr;
460 }
461
462 int HeapShared::append_root(oop obj) {
463 assert(SafepointSynchronize::is_at_safepoint(), "sanity");
464 assert(CDSConfig::is_dumping_heap(), "dump-time only");
465 assert(_pending_roots != nullptr, "sanity");
466
467 if (obj == nullptr) {
468 assert(_pending_roots->at(0) == nullptr, "root index 0 always maps to null");
469 return 0;
470 } else if (CDSConfig::is_dumping_aot_linked_classes()) {
471 // The AOT compiler may refer the same obj many times, so we
472 // should use the same index for this oop to avoid excessive entries
473 // in the roots array.
474 CachedOopInfo* obj_info = get_cached_oop_info(obj);
475 assert(obj_info != nullptr, "must be archived");
476
477 if (obj_info->root_index() > 0) {
478 return obj_info->root_index();
479 } else {
480 assert(obj_info->root_index() < 0, "must not be zero");
481 int i = _pending_roots->append(obj);
482 obj_info->set_root_index(i);
483 return i;
484 }
485 } else {
486 return _pending_roots->append(obj);
487 }
488 }
489
490 int HeapShared::get_root_index(oop obj) {
491 if (java_lang_Class::is_instance(obj)) {
492 obj = scratch_java_mirror(obj);
493 }
494
495 CachedOopInfo* obj_info = get_cached_oop_info(obj);
496 const char* error = nullptr;
497 if (obj_info == nullptr) {
498 error = "Not a cached oop";
499 } else if (obj_info->root_index() < 0) {
500 error = "Not a cached oop root";
501 } else {
502 return obj_info->root_index();
503 }
504
505 ResourceMark rm;
506 log_debug(aot, codecache, oops)("%s: " INTPTR_FORMAT " (%s)", error,
507 cast_from_oop<uintptr_t>(obj),
508 obj->klass()->external_name());
509 return -1;
510 }
511
512 oop HeapShared::get_root(int index, bool clear) {
513 assert(index >= 0, "sanity");
514 assert(is_archived_heap_in_use(), "getting roots into heap that is not used");
515
516 oop result;
517 if (HeapShared::is_loading_streaming_mode()) {
518 result = AOTStreamedHeapLoader::get_root(index);
519 } else {
520 assert(HeapShared::is_loading_mapping_mode(), "must be");
521 result = AOTMappedHeapLoader::get_root(index);
522 }
523
524 if (clear) {
525 clear_root(index);
526 }
527
528 return result;
529 }
530
531 void HeapShared::finish_materialize_objects() {
532 if (AOTStreamedHeapLoader::is_in_use()) {
533 AOTStreamedHeapLoader::finish_materialize_objects();
534 }
535 }
536
537 void HeapShared::clear_root(int index) {
538 if (CDSConfig::is_using_aot_linked_classes()) {
539 // When AOT linked classes are in use, all roots will be in use all
540 // the time, there's no benefit for clearing the roots. Also, we
541 // can't clear the roots as they can be shared.
542 return;
543 }
544
545 assert(index >= 0, "sanity");
546 assert(CDSConfig::is_using_archive(), "must be");
547 if (is_archived_heap_in_use()) {
548 if (log_is_enabled(Debug, aot, heap)) {
549 log_debug(aot, heap)("Clearing root %d: was %zu", index, p2i(get_root(index, false /* clear */)));
550 }
551 if (HeapShared::is_loading_streaming_mode()) {
552 AOTStreamedHeapLoader::clear_root(index);
553 } else {
554 assert(HeapShared::is_loading_mapping_mode(), "must be");
555 AOTMappedHeapLoader::clear_root(index);
556 }
557 }
558 }
559
560 bool HeapShared::archive_object(oop obj, oop referrer, KlassSubGraphInfo* subgraph_info) {
561 assert(CDSConfig::is_dumping_heap(), "dump-time only");
562
563 assert(!obj->is_stackChunk(), "do not archive stack chunks");
564 if (has_been_archived(obj)) {
565 return true;
566 }
567
568 if (is_too_large_to_archive(obj)) {
569 log_debug(aot, heap)("Cannot archive, object (" PTR_FORMAT ") is too large: %zu",
570 p2i(obj), obj->size());
571 debug_trace();
572 return false;
573 }
574
575 AOTOopChecker::check(obj); // Make sure contents of this oop are safe.
576 count_allocation(obj->size());
577
578 if (HeapShared::is_writing_streaming_mode()) {
579 AOTStreamedHeapWriter::add_source_obj(obj);
580 } else {
581 AOTMappedHeapWriter::add_source_obj(obj);
582 }
583
584 OopHandle oh(Universe::vm_global(), obj);
585 CachedOopInfo info = make_cached_oop_info(obj, referrer);
586 archived_object_cache()->put_when_absent(oh, info);
587 archived_object_cache()->maybe_grow();
588
589 Klass* k = obj->klass();
590 if (k->is_instance_klass()) {
591 // Whenever we see a non-array Java object of type X, we mark X to be aot-initialized.
592 // This ensures that during the production run, whenever Java code sees a cached object
593 // of type X, we know that X is already initialized. (see TODO comment below ...)
594
595 if (InstanceKlass::cast(k)->is_enum_subclass()
596 // We can't rerun <clinit> of enum classes (see cdsEnumKlass.cpp) so
597 // we must store them as AOT-initialized.
598 || (subgraph_info == _dump_time_special_subgraph))
599 // TODO: we do this only for the special subgraph for now. Extending this to
600 // other subgraphs would require more refactoring of the core library (such as
601 // move some initialization logic into runtimeSetup()).
602 //
603 // For the other subgraphs, we have a weaker mechanism to ensure that
604 // all classes in a subgraph are initialized before the subgraph is programmatically
605 // returned from jdk.internal.misc.CDS::initializeFromArchive().
606 // See HeapShared::initialize_from_archived_subgraph().
607 {
608 AOTArtifactFinder::add_aot_inited_class(InstanceKlass::cast(k));
609 }
610
611 if (java_lang_Class::is_instance(obj)) {
612 Klass* mirror_k = java_lang_Class::as_Klass(obj);
613 if (mirror_k != nullptr) {
614 AOTArtifactFinder::add_cached_class(mirror_k);
615 }
616 } else if (java_lang_invoke_ResolvedMethodName::is_instance(obj)) {
617 Method* m = java_lang_invoke_ResolvedMethodName::vmtarget(obj);
618 if (m != nullptr) {
619 if (RegeneratedClasses::has_been_regenerated(m)) {
620 m = RegeneratedClasses::get_regenerated_object(m);
621 }
622 InstanceKlass* method_holder = m->method_holder();
623 AOTArtifactFinder::add_cached_class(method_holder);
624 }
625 } else if (AOTCodeCache::is_dumping_code() &&
626 (java_lang_invoke_MethodHandle::is_instance(obj) || is_interned_string(obj))) {
627 // Needed by AOT compiler.
628 append_root(obj);
629 }
630 }
631
632 if (log_is_enabled(Debug, aot, heap)) {
633 ResourceMark rm;
634 LogTarget(Debug, aot, heap) log;
635 LogStream out(log);
636 out.print("Archived heap object " PTR_FORMAT " : %s ",
637 p2i(obj), obj->klass()->external_name());
638 if (java_lang_Class::is_instance(obj)) {
639 Klass* k = java_lang_Class::as_Klass(obj);
640 if (k != nullptr) {
641 out.print("%s", k->external_name());
642 } else {
643 out.print("primitive");
644 }
645 }
646 out.cr();
647 }
648
649 return true;
650 }
651
652 class MetaspaceObjToOopHandleTable: public HashTable<MetaspaceObj*, OopHandle,
653 36137, // prime number
654 AnyObj::C_HEAP,
655 mtClassShared> {
656 public:
657 oop get_oop(MetaspaceObj* ptr) {
658 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
659 OopHandle* handle = get(ptr);
660 if (handle != nullptr) {
661 return handle->resolve();
662 } else {
663 return nullptr;
664 }
665 }
666 void set_oop(MetaspaceObj* ptr, oop o) {
667 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
668 OopHandle handle(Universe::vm_global(), o);
669 put_when_absent(ptr, handle);
670 }
671 void remove_oop(MetaspaceObj* ptr) {
672 MutexLocker ml(ScratchObjects_lock, Mutex::_no_safepoint_check_flag);
673 OopHandle* handle = get(ptr);
674 if (handle != nullptr) {
675 handle->release(Universe::vm_global());
676 remove(ptr);
677 }
678 }
679 };
680
681 void HeapShared::add_scratch_resolved_references(ConstantPool* src, objArrayOop dest) {
682 if (CDSConfig::is_dumping_preimage_static_archive() && scratch_resolved_references(src) != nullptr) {
683 // We are in AOT training run. The class has been redefined and we are giving it a new resolved_reference.
684 // Ignore it, as this class will be excluded from the AOT config.
685 return;
686 }
687 if (SystemDictionaryShared::is_builtin_loader(src->pool_holder()->class_loader_data())) {
688 _scratch_objects_table->set_oop(src, dest);
689 }
690 }
691
692 objArrayOop HeapShared::scratch_resolved_references(ConstantPool* src) {
693 return (objArrayOop)_scratch_objects_table->get_oop(src);
694 }
695
696 void HeapShared::init_dumping() {
697 _scratch_objects_table = new (mtClass)MetaspaceObjToOopHandleTable();
698 _pending_roots = new GrowableArrayCHeap<oop, mtClassShared>(500);
699 _pending_roots->append(nullptr); // root index 0 represents a null oop
700 }
701
702 void HeapShared::init_scratch_objects_for_basic_type_mirrors(TRAPS) {
703 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
704 BasicType bt = (BasicType)i;
705 if (!is_reference_type(bt)) {
706 oop m = java_lang_Class::create_basic_type_mirror(type2name(bt), bt, CHECK);
707 _scratch_basic_type_mirrors[i] = OopHandle(Universe::vm_global(), m);
708 }
709 }
710 }
711
712 // Given java_mirror that represents a (primitive or reference) type T,
713 // return the "scratch" version that represents the same type T. Note
714 // that java_mirror will be returned if the mirror is already a scratch mirror.
715 //
716 // See java_lang_Class::create_scratch_mirror() for more info.
717 oop HeapShared::scratch_java_mirror(oop java_mirror) {
718 assert(java_lang_Class::is_instance(java_mirror), "must be");
719
720 for (int i = T_BOOLEAN; i < T_VOID+1; i++) {
721 BasicType bt = (BasicType)i;
722 if (!is_reference_type(bt)) {
723 if (_scratch_basic_type_mirrors[i].resolve() == java_mirror) {
724 return java_mirror;
725 }
726 }
727 }
728
729 if (java_lang_Class::is_primitive(java_mirror)) {
730 return scratch_java_mirror(java_lang_Class::as_BasicType(java_mirror));
731 } else {
732 return scratch_java_mirror(java_lang_Class::as_Klass(java_mirror));
733 }
734 }
735
736 oop HeapShared::scratch_java_mirror(BasicType t) {
737 assert((uint)t < T_VOID+1, "range check");
738 assert(!is_reference_type(t), "sanity");
739 return _scratch_basic_type_mirrors[t].resolve();
740 }
741
742 oop HeapShared::scratch_java_mirror(Klass* k) {
743 return _scratch_objects_table->get_oop(k);
744 }
745
746 void HeapShared::set_scratch_java_mirror(Klass* k, oop mirror) {
747 _scratch_objects_table->set_oop(k, mirror);
748 }
749
750 void HeapShared::remove_scratch_objects(Klass* k) {
751 // Klass is being deallocated. Java mirror can still be alive, and it should not
752 // point to dead klass. We need to break the link from mirror to the Klass.
753 // See how InstanceKlass::deallocate_contents does it for normal mirrors.
754 oop mirror = _scratch_objects_table->get_oop(k);
755 if (mirror != nullptr) {
756 java_lang_Class::set_klass(mirror, nullptr);
757 }
758 _scratch_objects_table->remove_oop(k);
759 if (k->is_instance_klass()) {
760 _scratch_objects_table->remove(InstanceKlass::cast(k)->constants());
761 }
762 }
763
764 //TODO: we eventually want a more direct test for these kinds of things.
765 //For example the JVM could record some bit of context from the creation
766 //of the klass, such as who called the hidden class factory. Using
767 //string compares on names is fragile and will break as soon as somebody
768 //changes the names in the JDK code. See discussion in JDK-8342481 for
769 //related ideas about marking AOT-related classes.
770 bool HeapShared::is_lambda_form_klass(InstanceKlass* ik) {
771 return ik->is_hidden() &&
772 (ik->name()->starts_with("java/lang/invoke/LambdaForm$MH+") ||
773 ik->name()->starts_with("java/lang/invoke/LambdaForm$DMH+") ||
774 ik->name()->starts_with("java/lang/invoke/LambdaForm$BMH+") ||
775 ik->name()->starts_with("java/lang/invoke/LambdaForm$VH+"));
776 }
777
778 bool HeapShared::is_lambda_proxy_klass(InstanceKlass* ik) {
779 return ik->is_hidden() && (ik->name()->index_of_at(0, "$$Lambda+", 9) > 0);
780 }
781
782 bool HeapShared::is_string_concat_klass(InstanceKlass* ik) {
783 return ik->is_hidden() && ik->name()->starts_with("java/lang/String$$StringConcat");
784 }
785
786 bool HeapShared::is_archivable_hidden_klass(InstanceKlass* ik) {
787 return CDSConfig::is_dumping_method_handles() &&
788 (is_lambda_form_klass(ik) || is_lambda_proxy_klass(ik) || is_string_concat_klass(ik));
789 }
790
791
792 void HeapShared::copy_and_rescan_aot_inited_mirror(InstanceKlass* ik) {
793 ik->set_has_aot_initialized_mirror();
794
795 oop orig_mirror;
796 if (RegeneratedClasses::is_regenerated_object(ik)) {
797 InstanceKlass* orig_ik = RegeneratedClasses::get_original_object(ik);
798 precond(orig_ik->is_initialized());
799 orig_mirror = orig_ik->java_mirror();
800 } else {
801 precond(ik->is_initialized());
802 orig_mirror = ik->java_mirror();
803 }
804
805 oop m = scratch_java_mirror(ik);
806 int nfields = 0;
807 for (JavaFieldStream fs(ik); !fs.done(); fs.next()) {
808 if (fs.access_flags().is_static()) {
809 fieldDescriptor& fd = fs.field_descriptor();
810 int offset = fd.offset();
811 switch (fd.field_type()) {
812 case T_OBJECT:
813 case T_ARRAY:
814 {
815 oop field_obj = orig_mirror->obj_field(offset);
816 m->obj_field_put(offset, field_obj);
817 if (field_obj != nullptr) {
818 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, field_obj);
819 assert(success, "sanity");
820 }
821 }
822 break;
823 case T_BOOLEAN:
824 m->bool_field_put(offset, orig_mirror->bool_field(offset));
825 break;
826 case T_BYTE:
827 m->byte_field_put(offset, orig_mirror->byte_field(offset));
828 break;
829 case T_SHORT:
830 m->short_field_put(offset, orig_mirror->short_field(offset));
831 break;
832 case T_CHAR:
833 m->char_field_put(offset, orig_mirror->char_field(offset));
834 break;
835 case T_INT:
836 m->int_field_put(offset, orig_mirror->int_field(offset));
837 break;
838 case T_LONG:
839 m->long_field_put(offset, orig_mirror->long_field(offset));
840 break;
841 case T_FLOAT:
842 m->float_field_put(offset, orig_mirror->float_field(offset));
843 break;
844 case T_DOUBLE:
845 m->double_field_put(offset, orig_mirror->double_field(offset));
846 break;
847 default:
848 ShouldNotReachHere();
849 }
850 nfields ++;
851 }
852 }
853
854 oop class_data = java_lang_Class::class_data(orig_mirror);
855 java_lang_Class::set_class_data(m, class_data);
856 if (class_data != nullptr) {
857 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, class_data);
858 assert(success, "sanity");
859 }
860
861 if (log_is_enabled(Debug, aot, init)) {
862 ResourceMark rm;
863 log_debug(aot, init)("copied %3d field(s) in aot-initialized mirror %s%s%s", nfields, ik->external_name(),
864 ik->is_hidden() ? " (hidden)" : "",
865 ik->is_enum_subclass() ? " (enum)" : "");
866 }
867 }
868
869 void HeapShared::copy_java_mirror(oop orig_mirror, oop scratch_m) {
870 // We need to retain the identity_hash, because it may have been used by some hashtables
871 // in the shared heap.
872 if (!orig_mirror->fast_no_hash_check()) {
873 intptr_t src_hash = orig_mirror->identity_hash();
874 if (UseCompactObjectHeaders) {
875 narrowKlass nk = CompressedKlassPointers::encode(orig_mirror->klass());
876 scratch_m->set_mark(markWord::prototype().set_narrow_klass(nk).copy_set_hash(src_hash));
877 } else {
878 scratch_m->set_mark(markWord::prototype().copy_set_hash(src_hash));
879 }
880 assert(scratch_m->mark().is_unlocked(), "sanity");
881
882 DEBUG_ONLY(intptr_t archived_hash = scratch_m->identity_hash());
883 assert(src_hash == archived_hash, "Different hash codes: original " INTPTR_FORMAT ", archived " INTPTR_FORMAT, src_hash, archived_hash);
884 }
885
886 if (CDSConfig::is_dumping_aot_linked_classes()) {
887 java_lang_Class::set_module(scratch_m, java_lang_Class::module(orig_mirror));
888 java_lang_Class::set_protection_domain(scratch_m, java_lang_Class::protection_domain(orig_mirror));
889 }
890
891 Klass* k = java_lang_Class::as_Klass(orig_mirror); // is null Universe::void_mirror();
892 if (CDSConfig::is_dumping_reflection_data() &&
893 k != nullptr && k->is_instance_klass() &&
894 java_lang_Class::reflection_data(orig_mirror) != nullptr &&
895 AOTConstantPoolResolver::can_archive_reflection_data(InstanceKlass::cast(k))) {
896 java_lang_Class::set_reflection_data(scratch_m, java_lang_Class::reflection_data(orig_mirror));
897 }
898 }
899
900 static objArrayOop get_archived_resolved_references(InstanceKlass* src_ik) {
901 if (SystemDictionaryShared::is_builtin_loader(src_ik->class_loader_data())) {
902 objArrayOop rr = src_ik->constants()->resolved_references_or_null();
903 if (rr != nullptr && !HeapShared::is_too_large_to_archive(rr)) {
904 return HeapShared::scratch_resolved_references(src_ik->constants());
905 }
906 }
907 return nullptr;
908 }
909
910 int HeapShared::archive_exception_instance(oop exception) {
911 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, exception);
912 assert(success, "sanity");
913 return append_root(exception);
914 }
915
916 void HeapShared::get_pointer_info(oop src_obj, bool& has_oop_pointers, bool& has_native_pointers) {
917 OopHandle oh(&src_obj);
918 CachedOopInfo* info = archived_object_cache()->get(oh);
919 assert(info != nullptr, "must be");
920 has_oop_pointers = info->has_oop_pointers();
921 has_native_pointers = info->has_native_pointers();
922 }
923
924 void HeapShared::set_has_native_pointers(oop src_obj) {
925 OopHandle oh(&src_obj);
926 CachedOopInfo* info = archived_object_cache()->get(oh);
927 assert(info != nullptr, "must be");
928 info->set_has_native_pointers();
929 }
930
931 // Between start_scanning_for_oops() and end_scanning_for_oops(), we discover all Java heap objects that
932 // should be stored in the AOT cache. The scanning is coordinated by AOTArtifactFinder.
933 void HeapShared::start_scanning_for_oops() {
934 {
935 NoSafepointVerifier nsv;
936
937 // The special subgraph doesn't belong to any class. We use Object_klass() here just
938 // for convenience.
939 _dump_time_special_subgraph = init_subgraph_info(vmClasses::Object_klass(), false);
940
941 // Cache for recording where the archived objects are copied to
942 create_archived_object_cache();
943
944 if (HeapShared::is_writing_mapping_mode() && (UseG1GC || UseCompressedOops)) {
945 aot_log_info(aot)("Heap range = [" PTR_FORMAT " - " PTR_FORMAT "]",
946 UseCompressedOops ? p2i(CompressedOops::begin()) :
947 p2i((address)G1CollectedHeap::heap()->reserved().start()),
948 UseCompressedOops ? p2i(CompressedOops::end()) :
949 p2i((address)G1CollectedHeap::heap()->reserved().end()));
950 }
951
952 archive_subgraphs();
953 }
954
955 init_seen_objects_table();
956 Universe::archive_exception_instances();
957 }
958
959 void HeapShared::end_scanning_for_oops() {
960 if (is_writing_mapping_mode()) {
961 StringTable::init_shared_table();
962 }
963 delete_seen_objects_table();
964 }
965
966 void HeapShared::write_heap(AOTMappedHeapInfo* mapped_heap_info, AOTStreamedHeapInfo* streamed_heap_info) {
967 {
968 NoSafepointVerifier nsv;
969 if (!SkipArchiveHeapVerification) {
970 CDSHeapVerifier::verify();
971 }
972 check_special_subgraph_classes();
973 }
974
975 if (HeapShared::is_writing_mapping_mode()) {
976 StringTable::write_shared_table();
977 AOTMappedHeapWriter::write(_pending_roots, mapped_heap_info);
978 } else {
979 assert(HeapShared::is_writing_streaming_mode(), "are there more modes?");
980 AOTStreamedHeapWriter::write(_pending_roots, streamed_heap_info);
981 }
982
983 ArchiveBuilder::OtherROAllocMark mark;
984 write_subgraph_info_table();
985
986 delete _pending_roots;
987 _pending_roots = nullptr;
988
989 make_archived_object_cache_gc_safe();
990 }
991
992 void HeapShared::scan_java_mirror(oop orig_mirror) {
993 oop m = scratch_java_mirror(orig_mirror);
994 if (m != nullptr) { // nullptr if for custom class loader
995 copy_java_mirror(orig_mirror, m);
996 bool success = archive_reachable_objects_from(1, _dump_time_special_subgraph, m);
997 assert(success, "sanity");
998
999 oop extra;
1000 if ((extra = java_lang_Class::reflection_data(m)) != nullptr) {
1001 success = archive_reachable_objects_from(1, _dump_time_special_subgraph, extra);
1002 assert(success, "sanity");
1003 }
1004 }
1005 }
1006
1007 void HeapShared::scan_java_class(Klass* orig_k) {
1008 scan_java_mirror(orig_k->java_mirror());
1009
1010 if (orig_k->is_instance_klass()) {
1011 InstanceKlass* orig_ik = InstanceKlass::cast(orig_k);
1012 orig_ik->constants()->prepare_resolved_references_for_archiving();
1013 objArrayOop rr = get_archived_resolved_references(orig_ik);
1014 if (rr != nullptr) {
1015 bool success = HeapShared::archive_reachable_objects_from(1, _dump_time_special_subgraph, rr);
1016 assert(success, "must be");
1017 }
1018 }
1019 }
1020
1021 void HeapShared::archive_subgraphs() {
1022 assert(CDSConfig::is_dumping_heap(), "must be");
1023
1024 if (CDSConfig::is_dumping_klass_subgraphs()) {
1025 archive_object_subgraphs(archive_subgraph_entry_fields,
1026 false /* is_full_module_graph */);
1027 if (CDSConfig::is_dumping_full_module_graph()) {
1028 archive_object_subgraphs(fmg_archive_subgraph_entry_fields,
1029 true /* is_full_module_graph */);
1030 }
1031 }
1032 }
1033
1034 //
1035 // Subgraph archiving support
1036 //
1037 HeapShared::DumpTimeKlassSubGraphInfoTable* HeapShared::_dump_time_subgraph_info_table = nullptr;
1038 HeapShared::RunTimeKlassSubGraphInfoTable HeapShared::_run_time_subgraph_info_table;
1039
1040 // Get the subgraph_info for Klass k. A new subgraph_info is created if
1041 // there is no existing one for k. The subgraph_info records the "buffered"
1042 // address of the class.
1043 KlassSubGraphInfo* HeapShared::init_subgraph_info(Klass* k, bool is_full_module_graph) {
1044 assert(CDSConfig::is_dumping_heap(), "dump time only");
1045 bool created;
1046 KlassSubGraphInfo* info =
1047 _dump_time_subgraph_info_table->put_if_absent(k, KlassSubGraphInfo(k, is_full_module_graph),
1048 &created);
1049 assert(created, "must not initialize twice");
1050 return info;
1051 }
1052
1053 KlassSubGraphInfo* HeapShared::get_subgraph_info(Klass* k) {
1054 assert(CDSConfig::is_dumping_heap(), "dump time only");
1055 KlassSubGraphInfo* info = _dump_time_subgraph_info_table->get(k);
1056 assert(info != nullptr, "must have been initialized");
1057 return info;
1058 }
1059
1060 // Add an entry field to the current KlassSubGraphInfo.
1061 void KlassSubGraphInfo::add_subgraph_entry_field(int static_field_offset, oop v) {
1062 assert(CDSConfig::is_dumping_heap(), "dump time only");
1063 if (_subgraph_entry_fields == nullptr) {
1064 _subgraph_entry_fields =
1065 new (mtClass) GrowableArray<int>(10, mtClass);
1066 }
1067 _subgraph_entry_fields->append(static_field_offset);
1068
1069 // Leyden: Temp fix for JDK-8371655 {
1070 if (v == nullptr) {
1071 _subgraph_entry_fields->append(-1);
1072 } else {
1073 _subgraph_entry_fields->append(HeapShared::append_root(v));
1074 }
1075 // }
1076 }
1077
1078 // Add the Klass* for an object in the current KlassSubGraphInfo's subgraphs.
1079 // Only objects of boot classes can be included in sub-graph.
1080 void KlassSubGraphInfo::add_subgraph_object_klass(Klass* orig_k) {
1081 assert(CDSConfig::is_dumping_heap(), "dump time only");
1082
1083 if (_subgraph_object_klasses == nullptr) {
1084 _subgraph_object_klasses =
1085 new (mtClass) GrowableArray<Klass*>(50, mtClass);
1086 }
1087
1088 if (_k == orig_k) {
1089 // Don't add the Klass containing the sub-graph to it's own klass
1090 // initialization list.
1091 return;
1092 }
1093
1094 if (orig_k->is_instance_klass()) {
1095 #ifdef ASSERT
1096 InstanceKlass* ik = InstanceKlass::cast(orig_k);
1097 if (CDSConfig::is_dumping_method_handles()) {
1098 // -XX:AOTInitTestClass must be used carefully in regression tests to
1099 // include only classes that are safe to aot-initialize.
1100 assert(ik->class_loader() == nullptr ||
1101 HeapShared::is_lambda_proxy_klass(ik) ||
1102 AOTClassInitializer::has_test_class(),
1103 "we can archive only instances of boot classes or lambda proxy classes");
1104 } else {
1105 assert(ik->class_loader() == nullptr, "must be boot class");
1106 }
1107 #endif
1108 // vmClasses::xxx_klass() are not updated, need to check
1109 // the original Klass*
1110 if (orig_k == vmClasses::String_klass() ||
1111 orig_k == vmClasses::Object_klass()) {
1112 // Initialized early during VM initialization. No need to be added
1113 // to the sub-graph object class list.
1114 return;
1115 }
1116 check_allowed_klass(InstanceKlass::cast(orig_k));
1117 } else if (orig_k->is_objArray_klass()) {
1118 Klass* abk = ObjArrayKlass::cast(orig_k)->bottom_klass();
1119 if (abk->is_instance_klass()) {
1120 assert(InstanceKlass::cast(abk)->defined_by_boot_loader(),
1121 "must be boot class");
1122 check_allowed_klass(InstanceKlass::cast(ObjArrayKlass::cast(orig_k)->bottom_klass()));
1123 }
1124 if (orig_k == Universe::objectArrayKlass()) {
1125 // Initialized early during Universe::genesis. No need to be added
1126 // to the list.
1127 return;
1128 }
1129 } else {
1130 assert(orig_k->is_typeArray_klass(), "must be");
1131 // Primitive type arrays are created early during Universe::genesis.
1132 return;
1133 }
1134
1135 if (log_is_enabled(Debug, aot, heap)) {
1136 if (!_subgraph_object_klasses->contains(orig_k)) {
1137 ResourceMark rm;
1138 log_debug(aot, heap)("Adding klass %s", orig_k->external_name());
1139 }
1140 }
1141
1142 _subgraph_object_klasses->append_if_missing(orig_k);
1143 _has_non_early_klasses |= is_non_early_klass(orig_k);
1144 }
1145
1146 void KlassSubGraphInfo::check_allowed_klass(InstanceKlass* ik) {
1147 #ifndef PRODUCT
1148 if (AOTClassInitializer::has_test_class()) {
1149 // The tests can cache arbitrary types of objects.
1150 return;
1151 }
1152 #endif
1153
1154 if (ik->module()->name() == vmSymbols::java_base()) {
1155 assert(ik->package() != nullptr, "classes in java.base cannot be in unnamed package");
1156 return;
1157 }
1158
1159 const char* lambda_msg = "";
1160 if (CDSConfig::is_dumping_method_handles()) {
1161 lambda_msg = ", or a lambda proxy class";
1162 if (HeapShared::is_lambda_proxy_klass(ik) &&
1163 (ik->class_loader() == nullptr ||
1164 ik->class_loader() == SystemDictionary::java_platform_loader() ||
1165 ik->class_loader() == SystemDictionary::java_system_loader())) {
1166 return;
1167 }
1168 }
1169
1170 #ifndef PRODUCT
1171 if (!ik->module()->is_named() && ik->package() == nullptr && ArchiveHeapTestClass != nullptr) {
1172 // This class is loaded by ArchiveHeapTestClass
1173 return;
1174 }
1175 const char* testcls_msg = ", or a test class in an unnamed package of an unnamed module";
1176 #else
1177 const char* testcls_msg = "";
1178 #endif
1179
1180 ResourceMark rm;
1181 log_error(aot, heap)("Class %s not allowed in archive heap. Must be in java.base%s%s",
1182 ik->external_name(), lambda_msg, testcls_msg);
1183 AOTMetaspace::unrecoverable_writing_error();
1184 }
1185
1186 bool KlassSubGraphInfo::is_non_early_klass(Klass* k) {
1187 if (k->is_objArray_klass()) {
1188 k = ObjArrayKlass::cast(k)->bottom_klass();
1189 }
1190 if (k->is_instance_klass()) {
1191 if (!SystemDictionaryShared::is_early_klass(InstanceKlass::cast(k))) {
1192 ResourceMark rm;
1193 log_info(aot, heap)("non-early: %s", k->external_name());
1194 return true;
1195 } else {
1196 return false;
1197 }
1198 } else {
1199 return false;
1200 }
1201 }
1202
1203 // Initialize an archived subgraph_info_record from the given KlassSubGraphInfo.
1204 void ArchivedKlassSubGraphInfoRecord::init(KlassSubGraphInfo* info) {
1205 _k = ArchiveBuilder::get_buffered_klass(info->klass());
1206 _entry_field_records = nullptr;
1207 _subgraph_object_klasses = nullptr;
1208 _is_full_module_graph = info->is_full_module_graph();
1209
1210 if (_is_full_module_graph) {
1211 // Consider all classes referenced by the full module graph as early -- we will be
1212 // allocating objects of these classes during JVMTI early phase, so they cannot
1213 // be processed by (non-early) JVMTI ClassFileLoadHook
1214 _has_non_early_klasses = false;
1215 } else {
1216 _has_non_early_klasses = info->has_non_early_klasses();
1217 }
1218
1219 if (_has_non_early_klasses) {
1220 ResourceMark rm;
1221 log_info(aot, heap)(
1222 "Subgraph of klass %s has non-early klasses and cannot be used when JVMTI ClassFileLoadHook is enabled",
1223 _k->external_name());
1224 }
1225
1226 // populate the entry fields
1227 GrowableArray<int>* entry_fields = info->subgraph_entry_fields();
1228 if (entry_fields != nullptr) {
1229 int num_entry_fields = entry_fields->length();
1230 assert(num_entry_fields % 2 == 0, "sanity");
1231 _entry_field_records =
1232 ArchiveBuilder::new_ro_array<int>(num_entry_fields);
1233 for (int i = 0 ; i < num_entry_fields; i++) {
1234 _entry_field_records->at_put(i, entry_fields->at(i));
1235 }
1236 }
1237
1238 // <recorded_klasses> has the Klasses of all the objects that are referenced by this subgraph.
1239 // Copy those that need to be explicitly initialized into <_subgraph_object_klasses>.
1240 GrowableArray<Klass*>* recorded_klasses = info->subgraph_object_klasses();
1241 if (recorded_klasses != nullptr) {
1242 // AOT-inited classes are automatically marked as "initialized" during bootstrap. When
1243 // programmatically loading a subgraph, we only need to explicitly initialize the classes
1244 // that are not aot-inited.
1245 int num_to_copy = 0;
1246 for (int i = 0; i < recorded_klasses->length(); i++) {
1247 Klass* subgraph_k = ArchiveBuilder::get_buffered_klass(recorded_klasses->at(i));
1248 if (!subgraph_k->has_aot_initialized_mirror()) {
1249 num_to_copy ++;
1250 }
1251 }
1252
1253 _subgraph_object_klasses = ArchiveBuilder::new_ro_array<Klass*>(num_to_copy);
1254 bool is_special = (_k == ArchiveBuilder::get_buffered_klass(vmClasses::Object_klass()));
1255 for (int i = 0, n = 0; i < recorded_klasses->length(); i++) {
1256 Klass* subgraph_k = ArchiveBuilder::get_buffered_klass(recorded_klasses->at(i));
1257 if (subgraph_k->has_aot_initialized_mirror()) {
1258 continue;
1259 }
1260 if (log_is_enabled(Info, aot, heap)) {
1261 ResourceMark rm;
1262 const char* owner_name = is_special ? "<special>" : _k->external_name();
1263 if (subgraph_k->is_instance_klass()) {
1264 InstanceKlass* src_ik = InstanceKlass::cast(ArchiveBuilder::current()->get_source_addr(subgraph_k));
1265 }
1266 log_info(aot, heap)(
1267 "Archived object klass %s (%2d) => %s",
1268 owner_name, n, subgraph_k->external_name());
1269 }
1270 _subgraph_object_klasses->at_put(n, subgraph_k);
1271 ArchivePtrMarker::mark_pointer(_subgraph_object_klasses->adr_at(n));
1272 n++;
1273 }
1274 }
1275
1276 ArchivePtrMarker::mark_pointer(&_k);
1277 ArchivePtrMarker::mark_pointer(&_entry_field_records);
1278 ArchivePtrMarker::mark_pointer(&_subgraph_object_klasses);
1279 }
1280
1281 class HeapShared::CopyKlassSubGraphInfoToArchive : StackObj {
1282 CompactHashtableWriter* _writer;
1283 public:
1284 CopyKlassSubGraphInfoToArchive(CompactHashtableWriter* writer) : _writer(writer) {}
1285
1286 bool do_entry(Klass* klass, KlassSubGraphInfo& info) {
1287 if (info.subgraph_object_klasses() != nullptr || info.subgraph_entry_fields() != nullptr) {
1288 ArchivedKlassSubGraphInfoRecord* record = HeapShared::archive_subgraph_info(&info);
1289 Klass* buffered_k = ArchiveBuilder::get_buffered_klass(klass);
1290 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary((address)buffered_k);
1291 _writer->add(hash, AOTCompressedPointers::encode_not_null(record));
1292 }
1293 return true; // keep on iterating
1294 }
1295 };
1296
1297 ArchivedKlassSubGraphInfoRecord* HeapShared::archive_subgraph_info(KlassSubGraphInfo* info) {
1298 ArchivedKlassSubGraphInfoRecord* record =
1299 (ArchivedKlassSubGraphInfoRecord*)ArchiveBuilder::ro_region_alloc(sizeof(ArchivedKlassSubGraphInfoRecord));
1300 record->init(info);
1301 if (info == _dump_time_special_subgraph) {
1302 _run_time_special_subgraph = record;
1303 }
1304 return record;
1305 }
1306
1307 // Build the records of archived subgraph infos, which include:
1308 // - Entry points to all subgraphs from the containing class mirror. The entry
1309 // points are static fields in the mirror. For each entry point, the field
1310 // offset, and value are recorded in the sub-graph
1311 // info. The value is stored back to the corresponding field at runtime.
1312 // - A list of klasses that need to be loaded/initialized before archived
1313 // java object sub-graph can be accessed at runtime.
1314 void HeapShared::write_subgraph_info_table() {
1315 // Allocate the contents of the hashtable(s) inside the RO region of the CDS archive.
1316 DumpTimeKlassSubGraphInfoTable* d_table = _dump_time_subgraph_info_table;
1317 CompactHashtableStats stats;
1318
1319 _run_time_subgraph_info_table.reset();
1320
1321 CompactHashtableWriter writer(d_table->number_of_entries(), &stats);
1322 CopyKlassSubGraphInfoToArchive copy(&writer);
1323 d_table->iterate(©);
1324 writer.dump(&_run_time_subgraph_info_table, "subgraphs");
1325
1326 #ifndef PRODUCT
1327 if (ArchiveHeapTestClass != nullptr) {
1328 size_t len = strlen(ArchiveHeapTestClass) + 1;
1329 Array<char>* array = ArchiveBuilder::new_ro_array<char>((int)len);
1330 strncpy(array->adr_at(0), ArchiveHeapTestClass, len);
1331 _archived_ArchiveHeapTestClass = array;
1332 }
1333 #endif
1334 if (log_is_enabled(Info, aot, heap)) {
1335 print_stats();
1336 }
1337 }
1338
1339 void HeapShared::serialize_tables(SerializeClosure* soc) {
1340
1341 #ifndef PRODUCT
1342 soc->do_ptr(&_archived_ArchiveHeapTestClass);
1343 if (soc->reading() && _archived_ArchiveHeapTestClass != nullptr) {
1344 _test_class_name = _archived_ArchiveHeapTestClass->adr_at(0);
1345 setup_test_class(_test_class_name);
1346 }
1347 #endif
1348
1349 _run_time_subgraph_info_table.serialize_header(soc);
1350 soc->do_ptr(&_run_time_special_subgraph);
1351 }
1352
1353 static void verify_the_heap(Klass* k, const char* which) {
1354 if (VerifyArchivedFields > 0) {
1355 ResourceMark rm;
1356 log_info(aot, heap)("Verify heap %s initializing static field(s) in %s",
1357 which, k->external_name());
1358
1359 if (VerifyArchivedFields == 1) {
1360 VM_Verify verify_op;
1361 VMThread::execute(&verify_op);
1362 } else if (VerifyArchivedFields == 2 && is_init_completed()) {
1363 // At this time, the oop->klass() of some archived objects in the heap may not
1364 // have been loaded into the system dictionary yet. Nevertheless, oop->klass() should
1365 // have enough information (object size, oop maps, etc) so that a GC can be safely
1366 // performed.
1367 //
1368 // -XX:VerifyArchivedFields=2 force a GC to happen in such an early stage
1369 // to check for GC safety.
1370 log_info(aot, heap)("Trigger GC %s initializing static field(s) in %s",
1371 which, k->external_name());
1372 FlagSetting fs1(VerifyBeforeGC, true);
1373 FlagSetting fs2(VerifyDuringGC, true);
1374 FlagSetting fs3(VerifyAfterGC, true);
1375 Universe::heap()->collect(GCCause::_java_lang_system_gc);
1376 }
1377 }
1378 }
1379
1380 // Before GC can execute, we must ensure that all oops reachable from HeapShared::roots()
1381 // have a valid klass. I.e., oopDesc::klass() must have already been resolved.
1382 //
1383 // Note: if a ArchivedKlassSubGraphInfoRecord contains non-early classes, and JVMTI
1384 // ClassFileLoadHook is enabled, it's possible for this class to be dynamically replaced. In
1385 // this case, we will not load the ArchivedKlassSubGraphInfoRecord and will clear its roots.
1386 void HeapShared::resolve_classes(JavaThread* current) {
1387 assert(CDSConfig::is_using_archive(), "runtime only!");
1388 if (CDSConfig::is_using_klass_subgraphs()) {
1389 resolve_classes_for_subgraphs(current, archive_subgraph_entry_fields);
1390 resolve_classes_for_subgraphs(current, fmg_archive_subgraph_entry_fields);
1391 }
1392 }
1393
1394 void HeapShared::resolve_classes_for_subgraphs(JavaThread* current, ArchivableStaticFieldInfo fields[]) {
1395 for (int i = 0; fields[i].valid(); i++) {
1396 ArchivableStaticFieldInfo* info = &fields[i];
1397 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
1398 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name);
1399 assert(k != nullptr && k->defined_by_boot_loader(), "sanity");
1400 resolve_classes_for_subgraph_of(current, k);
1401 }
1402 }
1403
1404 void HeapShared::resolve_classes_for_subgraph_of(JavaThread* current, Klass* k) {
1405 JavaThread* THREAD = current;
1406 ExceptionMark em(THREAD);
1407 const ArchivedKlassSubGraphInfoRecord* record =
1408 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
1409 if (HAS_PENDING_EXCEPTION) {
1410 CLEAR_PENDING_EXCEPTION;
1411 }
1412 if (record == nullptr) {
1413 clear_archived_roots_of(k);
1414 }
1415 }
1416
1417 static const char* java_lang_invoke_core_klasses[] = {
1418 "java/lang/invoke/Invokers$Holder",
1419 "java/lang/invoke/MethodHandle",
1420 "java/lang/invoke/MethodHandleNatives",
1421 "java/lang/invoke/DirectMethodHandle$Holder",
1422 "java/lang/invoke/DelegatingMethodHandle$Holder",
1423 "java/lang/invoke/LambdaForm$Holder",
1424 "java/lang/invoke/BoundMethodHandle$Species_L",
1425 };
1426
1427 void HeapShared::initialize_java_lang_invoke(TRAPS) {
1428 if (CDSConfig::is_using_aot_linked_classes() || CDSConfig::is_dumping_method_handles()) {
1429 int len = sizeof(java_lang_invoke_core_klasses)/sizeof(char*);
1430 for (int i = 0; i < len; i++) {
1431 resolve_or_init(java_lang_invoke_core_klasses[i], true, CHECK);
1432 }
1433 }
1434 }
1435
1436 // Initialize the InstanceKlasses of objects that are reachable from the following roots:
1437 // - interned strings
1438 // - Klass::java_mirror() -- including aot-initialized mirrors such as those of Enum klasses.
1439 // - ConstantPool::resolved_references()
1440 // - Universe::<xxx>_exception_instance()
1441 //
1442 // For example, if this enum class is initialized at AOT cache assembly time:
1443 //
1444 // enum Fruit {
1445 // APPLE, ORANGE, BANANA;
1446 // static final Set<Fruit> HAVE_SEEDS = new HashSet<>(Arrays.asList(APPLE, ORANGE));
1447 // }
1448 //
1449 // the aot-initialized mirror of Fruit has a static field that references HashSet, which
1450 // should be initialized before any Java code can access the Fruit class. Note that
1451 // HashSet itself doesn't necessary need to be an aot-initialized class.
1452 void HeapShared::init_classes_for_special_subgraph(Handle class_loader, TRAPS) {
1453 if (!is_archived_heap_in_use()) {
1454 return;
1455 }
1456
1457 assert( _run_time_special_subgraph != nullptr, "must be");
1458 Array<Klass*>* klasses = _run_time_special_subgraph->subgraph_object_klasses();
1459 if (klasses != nullptr) {
1460 for (int pass = 0; pass < 2; pass ++) {
1461 for (int i = 0; i < klasses->length(); i++) {
1462 Klass* k = klasses->at(i);
1463 if (k->class_loader_data() == nullptr) {
1464 // This class is not yet loaded. We will initialize it in a later phase.
1465 // For example, we have loaded only AOTLinkedClassCategory::BOOT1 classes
1466 // but k is part of AOTLinkedClassCategory::BOOT2.
1467 continue;
1468 }
1469 if (k->class_loader() == class_loader()) {
1470 if (pass == 0) {
1471 if (k->is_instance_klass()) {
1472 InstanceKlass::cast(k)->link_class(CHECK);
1473 }
1474 } else {
1475 resolve_or_init(k, /*do_init*/true, CHECK);
1476 }
1477 }
1478 }
1479 }
1480 }
1481 }
1482
1483 void HeapShared::initialize_from_archived_subgraph(JavaThread* current, Klass* k) {
1484 JavaThread* THREAD = current;
1485 if (!CDSConfig::is_using_klass_subgraphs()) {
1486 return; // nothing to do
1487 }
1488
1489 if (k->name()->equals("jdk/internal/module/ArchivedModuleGraph") &&
1490 !CDSConfig::is_using_optimized_module_handling() &&
1491 // archive was created with --module-path
1492 AOTClassLocationConfig::runtime()->num_module_paths() > 0) {
1493 // ArchivedModuleGraph was created with a --module-path that's different than the runtime --module-path.
1494 // Thus, it might contain references to modules that do not exist at runtime. We cannot use it.
1495 log_info(aot, heap)("Skip initializing ArchivedModuleGraph subgraph: is_using_optimized_module_handling=%s num_module_paths=%d",
1496 BOOL_TO_STR(CDSConfig::is_using_optimized_module_handling()),
1497 AOTClassLocationConfig::runtime()->num_module_paths());
1498 return;
1499 }
1500
1501 ExceptionMark em(THREAD);
1502 const ArchivedKlassSubGraphInfoRecord* record =
1503 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
1504
1505 if (HAS_PENDING_EXCEPTION) {
1506 CLEAR_PENDING_EXCEPTION;
1507 // None of the field value will be set if there was an exception when initializing the classes.
1508 // The java code will not see any of the archived objects in the
1509 // subgraphs referenced from k in this case.
1510 return;
1511 }
1512
1513 if (record != nullptr) {
1514 init_archived_fields_for(k, record);
1515 }
1516 }
1517
1518 const ArchivedKlassSubGraphInfoRecord*
1519 HeapShared::resolve_or_init_classes_for_subgraph_of(Klass* k, bool do_init, TRAPS) {
1520 assert(!CDSConfig::is_dumping_heap(), "Should not be called when dumping heap");
1521
1522 if (!k->in_aot_cache()) {
1523 return nullptr;
1524 }
1525 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1526 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1527
1528 #ifndef PRODUCT
1529 if (_test_class_name != nullptr && k->name()->equals(_test_class_name) && record != nullptr) {
1530 _test_class = k;
1531 _test_class_record = record;
1532 }
1533 #endif
1534
1535 // Initialize from archived data. Currently this is done only
1536 // during VM initialization time. No lock is needed.
1537 if (record == nullptr) {
1538 if (log_is_enabled(Info, aot, heap)) {
1539 ResourceMark rm(THREAD);
1540 log_info(aot, heap)("subgraph %s is not recorded",
1541 k->external_name());
1542 }
1543 return nullptr;
1544 } else {
1545 if (record->is_full_module_graph() && !CDSConfig::is_using_full_module_graph()) {
1546 if (log_is_enabled(Info, aot, heap)) {
1547 ResourceMark rm(THREAD);
1548 log_info(aot, heap)("subgraph %s cannot be used because full module graph is disabled",
1549 k->external_name());
1550 }
1551 return nullptr;
1552 }
1553
1554 if (record->has_non_early_klasses() && JvmtiExport::should_post_class_file_load_hook()) {
1555 if (log_is_enabled(Info, aot, heap)) {
1556 ResourceMark rm(THREAD);
1557 log_info(aot, heap)("subgraph %s cannot be used because JVMTI ClassFileLoadHook is enabled",
1558 k->external_name());
1559 }
1560 return nullptr;
1561 }
1562
1563 if (log_is_enabled(Info, aot, heap)) {
1564 ResourceMark rm;
1565 log_info(aot, heap)("%s subgraph %s ", do_init ? "init" : "resolve", k->external_name());
1566 }
1567
1568 resolve_or_init(k, do_init, CHECK_NULL);
1569
1570 // Load/link/initialize the klasses of the objects in the subgraph.
1571 // nullptr class loader is used.
1572 Array<Klass*>* klasses = record->subgraph_object_klasses();
1573 if (klasses != nullptr) {
1574 for (int i = 0; i < klasses->length(); i++) {
1575 Klass* klass = klasses->at(i);
1576 if (!klass->in_aot_cache()) {
1577 return nullptr;
1578 }
1579 resolve_or_init(klass, do_init, CHECK_NULL);
1580 }
1581 }
1582 }
1583
1584 return record;
1585 }
1586
1587 void HeapShared::resolve_or_init(const char* klass_name, bool do_init, TRAPS) {
1588 TempNewSymbol klass_name_sym = SymbolTable::new_symbol(klass_name);
1589 InstanceKlass* k = SystemDictionaryShared::find_builtin_class(klass_name_sym);
1590 if (k == nullptr) {
1591 return;
1592 }
1593 assert(k->defined_by_boot_loader(), "sanity");
1594 resolve_or_init(k, false, CHECK);
1595 if (do_init) {
1596 resolve_or_init(k, true, CHECK);
1597 }
1598 }
1599
1600 void HeapShared::resolve_or_init(Klass* k, bool do_init, TRAPS) {
1601 if (!do_init) {
1602 if (k->class_loader_data() == nullptr) {
1603 Klass* resolved_k = SystemDictionary::resolve_or_null(k->name(), CHECK);
1604 assert(resolved_k == k, "classes used by archived heap must not be replaced by JVMTI ClassFileLoadHook");
1605 }
1606 } else {
1607 assert(k->class_loader_data() != nullptr, "must have been resolved by HeapShared::resolve_classes");
1608 if (k->is_instance_klass()) {
1609 InstanceKlass* ik = InstanceKlass::cast(k);
1610 ik->initialize(CHECK);
1611 } else if (k->is_objArray_klass()) {
1612 ObjArrayKlass* oak = ObjArrayKlass::cast(k);
1613 oak->initialize(CHECK);
1614 }
1615 }
1616 }
1617
1618 void HeapShared::init_archived_fields_for(Klass* k, const ArchivedKlassSubGraphInfoRecord* record) {
1619 verify_the_heap(k, "before");
1620
1621 Array<int>* entry_field_records = record->entry_field_records();
1622 if (entry_field_records != nullptr) {
1623 int efr_len = entry_field_records->length();
1624 assert(efr_len % 2 == 0, "sanity");
1625 for (int i = 0; i < efr_len; i += 2) {
1626 int field_offset = entry_field_records->at(i);
1627 int root_index = entry_field_records->at(i+1);
1628 // Load the subgraph entry fields from the record and store them back to
1629 // the corresponding fields within the mirror.
1630
1631 // Leyden: Temp fix for JDK-8371655 {
1632 oop v;
1633 if (root_index < 0) {
1634 v = nullptr;
1635 } else {
1636 v = get_root(root_index, /*clear=*/true);
1637 }
1638 // }
1639
1640 oop m = k->java_mirror();
1641 if (k->has_aot_initialized_mirror()) {
1642 assert(v == m->obj_field(field_offset), "must be aot-initialized");
1643 } else {
1644 m->obj_field_put(field_offset, v);
1645 }
1646 log_debug(aot, heap)(" " PTR_FORMAT " init field @ %2d = " PTR_FORMAT, p2i(k), field_offset, p2i(v));
1647 }
1648
1649 // Done. Java code can see the archived sub-graphs referenced from k's
1650 // mirror after this point.
1651 if (log_is_enabled(Info, aot, heap)) {
1652 ResourceMark rm;
1653 log_info(aot, heap)("initialize_from_archived_subgraph %s " PTR_FORMAT "%s%s",
1654 k->external_name(), p2i(k), JvmtiExport::is_early_phase() ? " (early)" : "",
1655 k->has_aot_initialized_mirror() ? " (aot-inited)" : "");
1656 }
1657 }
1658
1659 verify_the_heap(k, "after ");
1660 }
1661
1662 void HeapShared::clear_archived_roots_of(Klass* k) {
1663 unsigned int hash = SystemDictionaryShared::hash_for_shared_dictionary_quick(k);
1664 const ArchivedKlassSubGraphInfoRecord* record = _run_time_subgraph_info_table.lookup(k, hash, 0);
1665 if (record != nullptr) {
1666 Array<int>* entry_field_records = record->entry_field_records();
1667 if (entry_field_records != nullptr) {
1668 int efr_len = entry_field_records->length();
1669 assert(efr_len % 2 == 0, "sanity");
1670 for (int i = 0; i < efr_len; i += 2) {
1671 int root_index = entry_field_records->at(i+1);
1672 clear_root(root_index);
1673 }
1674 }
1675 }
1676 }
1677
1678 // Push all oop fields (or oop array elemenets in case of an objArray) in
1679 // _referencing_obj onto the _stack.
1680 class HeapShared::OopFieldPusher: public BasicOopIterateClosure {
1681 PendingOopStack* _stack;
1682 GrowableArray<oop> _found_oop_fields;
1683 int _level;
1684 bool _record_klasses_only;
1685 KlassSubGraphInfo* _subgraph_info;
1686 oop _referencing_obj;
1687 bool _is_java_lang_ref;
1688 public:
1689 OopFieldPusher(PendingOopStack* stack,
1690 int level,
1691 bool record_klasses_only,
1692 KlassSubGraphInfo* subgraph_info,
1693 oop orig) :
1694 _stack(stack),
1695 _found_oop_fields(),
1696 _level(level),
1697 _record_klasses_only(record_klasses_only),
1698 _subgraph_info(subgraph_info),
1699 _referencing_obj(orig) {
1700 _is_java_lang_ref = AOTReferenceObjSupport::check_if_ref_obj(orig);
1701 }
1702 void do_oop(narrowOop *p) { OopFieldPusher::do_oop_work(p); }
1703 void do_oop( oop *p) { OopFieldPusher::do_oop_work(p); }
1704
1705 ~OopFieldPusher() {
1706 while (_found_oop_fields.length() > 0) {
1707 // This produces the exact same traversal order as the previous version
1708 // of OopFieldPusher that recurses on the C stack -- a depth-first search,
1709 // walking the oop fields in _referencing_obj by ascending field offsets.
1710 oop obj = _found_oop_fields.pop();
1711 _stack->push(PendingOop(obj, _referencing_obj, _level + 1));
1712 }
1713 }
1714
1715 protected:
1716 template <class T> void do_oop_work(T *p) {
1717 int field_offset = pointer_delta_as_int((char*)p, cast_from_oop<char*>(_referencing_obj));
1718 oop obj = HeapAccess<ON_UNKNOWN_OOP_REF>::oop_load_at(_referencing_obj, field_offset);
1719 if (obj != nullptr) {
1720 if (_is_java_lang_ref && AOTReferenceObjSupport::skip_field(field_offset)) {
1721 // Do not follow these fields. They will be cleared to null.
1722 return;
1723 }
1724
1725 if (!_record_klasses_only && log_is_enabled(Debug, aot, heap)) {
1726 ResourceMark rm;
1727 log_debug(aot, heap)("(%d) %s[%d] ==> " PTR_FORMAT " size %zu %s", _level,
1728 _referencing_obj->klass()->external_name(), field_offset,
1729 p2i(obj), obj->size() * HeapWordSize, obj->klass()->external_name());
1730 if (log_is_enabled(Trace, aot, heap)) {
1731 LogTarget(Trace, aot, heap) log;
1732 LogStream out(log);
1733 obj->print_on(&out);
1734 }
1735 }
1736
1737 _found_oop_fields.push(obj);
1738 }
1739 }
1740
1741 public:
1742 oop referencing_obj() { return _referencing_obj; }
1743 KlassSubGraphInfo* subgraph_info() { return _subgraph_info; }
1744 };
1745
1746 // Checks if an oop has any non-null oop fields
1747 class PointsToOopsChecker : public BasicOopIterateClosure {
1748 bool _result;
1749
1750 template <class T> void check(T *p) {
1751 _result |= (HeapAccess<>::oop_load(p) != nullptr);
1752 }
1753
1754 public:
1755 PointsToOopsChecker() : _result(false) {}
1756 void do_oop(narrowOop *p) { check(p); }
1757 void do_oop( oop *p) { check(p); }
1758 bool result() { return _result; }
1759 };
1760
1761 HeapShared::CachedOopInfo HeapShared::make_cached_oop_info(oop obj, oop referrer) {
1762 PointsToOopsChecker points_to_oops_checker;
1763 obj->oop_iterate(&points_to_oops_checker);
1764 return CachedOopInfo(OopHandle(Universe::vm_global(), referrer), points_to_oops_checker.result());
1765 }
1766
1767 void HeapShared::init_box_classes(TRAPS) {
1768 if (is_archived_heap_in_use()) {
1769 vmClasses::Boolean_klass()->initialize(CHECK);
1770 vmClasses::Character_klass()->initialize(CHECK);
1771 vmClasses::Float_klass()->initialize(CHECK);
1772 vmClasses::Double_klass()->initialize(CHECK);
1773 vmClasses::Byte_klass()->initialize(CHECK);
1774 vmClasses::Short_klass()->initialize(CHECK);
1775 vmClasses::Integer_klass()->initialize(CHECK);
1776 vmClasses::Long_klass()->initialize(CHECK);
1777 vmClasses::Void_klass()->initialize(CHECK);
1778 }
1779 }
1780
1781 // (1) If orig_obj has not been archived yet, archive it.
1782 // (2) If orig_obj has not been seen yet (since start_recording_subgraph() was called),
1783 // trace all objects that are reachable from it, and make sure these objects are archived.
1784 // (3) Record the klasses of all objects that are reachable from orig_obj (including those that
1785 // were already archived when this function is called)
1786 bool HeapShared::archive_reachable_objects_from(int level,
1787 KlassSubGraphInfo* subgraph_info,
1788 oop orig_obj) {
1789 assert(orig_obj != nullptr, "must be");
1790 PendingOopStack stack;
1791 stack.push(PendingOop(orig_obj, nullptr, level));
1792
1793 while (stack.length() > 0) {
1794 PendingOop po = stack.pop();
1795 _object_being_archived = po;
1796 bool status = walk_one_object(&stack, po.level(), subgraph_info, po.obj(), po.referrer());
1797 _object_being_archived = PendingOop();
1798
1799 if (!status) {
1800 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1801 // as the Java code will take care of initializing this field dynamically.
1802 assert(level == 1, "VM should have exited with unarchivable objects for _level > 1");
1803 return false;
1804 }
1805 }
1806
1807 return true;
1808 }
1809
1810 bool HeapShared::walk_one_object(PendingOopStack* stack, int level, KlassSubGraphInfo* subgraph_info,
1811 oop orig_obj, oop referrer) {
1812 assert(orig_obj != nullptr, "must be");
1813 if (!JavaClasses::is_supported_for_archiving(orig_obj)) {
1814 // This object has injected fields that cannot be supported easily, so we disallow them for now.
1815 // If you get an error here, you probably made a change in the JDK library that has added
1816 // these objects that are referenced (directly or indirectly) by static fields.
1817 ResourceMark rm;
1818 log_error(aot, heap)("Cannot archive object " PTR_FORMAT " of class %s", p2i(orig_obj), orig_obj->klass()->external_name());
1819 debug_trace();
1820 AOTMetaspace::unrecoverable_writing_error();
1821 }
1822
1823 if (log_is_enabled(Debug, aot, heap) && java_lang_Class::is_instance(orig_obj)) {
1824 ResourceMark rm;
1825 LogTarget(Debug, aot, heap) log;
1826 LogStream out(log);
1827 out.print("Found java mirror " PTR_FORMAT " ", p2i(orig_obj));
1828 Klass* k = java_lang_Class::as_Klass(orig_obj);
1829 if (k != nullptr) {
1830 out.print("%s", k->external_name());
1831 } else {
1832 out.print("primitive");
1833 }
1834 out.print_cr("; scratch mirror = " PTR_FORMAT,
1835 p2i(scratch_java_mirror(orig_obj)));
1836 }
1837
1838 if (java_lang_Class::is_instance(orig_obj)) {
1839 Klass* k = java_lang_Class::as_Klass(orig_obj);
1840 if (RegeneratedClasses::has_been_regenerated(k)) {
1841 orig_obj = RegeneratedClasses::get_regenerated_object(k)->java_mirror();
1842 }
1843 }
1844
1845 if (CDSConfig::is_dumping_aot_linked_classes()) {
1846 if (java_lang_Class::is_instance(orig_obj)) {
1847 orig_obj = scratch_java_mirror(orig_obj);
1848 assert(orig_obj != nullptr, "must be archived");
1849 }
1850 } else if (java_lang_Class::is_instance(orig_obj) && subgraph_info != _dump_time_special_subgraph) {
1851 // Without CDSConfig::is_dumping_aot_linked_classes(), we only allow archived objects to
1852 // point to the mirrors of (1) j.l.Object, (2) primitive classes, and (3) box classes. These are initialized
1853 // very early by HeapShared::init_box_classes().
1854 if (orig_obj == vmClasses::Object_klass()->java_mirror()
1855 || java_lang_Class::is_primitive(orig_obj)
1856 || orig_obj == vmClasses::Boolean_klass()->java_mirror()
1857 || orig_obj == vmClasses::Character_klass()->java_mirror()
1858 || orig_obj == vmClasses::Float_klass()->java_mirror()
1859 || orig_obj == vmClasses::Double_klass()->java_mirror()
1860 || orig_obj == vmClasses::Byte_klass()->java_mirror()
1861 || orig_obj == vmClasses::Short_klass()->java_mirror()
1862 || orig_obj == vmClasses::Integer_klass()->java_mirror()
1863 || orig_obj == vmClasses::Long_klass()->java_mirror()
1864 || orig_obj == vmClasses::Void_klass()->java_mirror()) {
1865 orig_obj = scratch_java_mirror(orig_obj);
1866 assert(orig_obj != nullptr, "must be archived");
1867 } else {
1868 // If you get an error here, you probably made a change in the JDK library that has added a Class
1869 // object that is referenced (directly or indirectly) by an ArchivableStaticFieldInfo
1870 // defined at the top of this file.
1871 log_error(aot, heap)("(%d) Unknown java.lang.Class object is in the archived sub-graph", level);
1872 debug_trace();
1873 AOTMetaspace::unrecoverable_writing_error();
1874 }
1875 }
1876
1877 if (has_been_seen_during_subgraph_recording(orig_obj)) {
1878 // orig_obj has already been archived and traced. Nothing more to do.
1879 return true;
1880 } else {
1881 set_has_been_seen_during_subgraph_recording(orig_obj);
1882 }
1883
1884 bool already_archived = has_been_archived(orig_obj);
1885 bool record_klasses_only = already_archived;
1886 if (!already_archived) {
1887 ++_num_new_archived_objs;
1888 if (!archive_object(orig_obj, referrer, subgraph_info)) {
1889 // Skip archiving the sub-graph referenced from the current entry field.
1890 ResourceMark rm;
1891 log_error(aot, heap)(
1892 "Cannot archive the sub-graph referenced from %s object ("
1893 PTR_FORMAT ") size %zu, skipped.",
1894 orig_obj->klass()->external_name(), p2i(orig_obj), orig_obj->size() * HeapWordSize);
1895 if (level == 1) {
1896 // Don't archive a subgraph root that's too big. For archives static fields, that's OK
1897 // as the Java code will take care of initializing this field dynamically.
1898 return false;
1899 } else {
1900 // We don't know how to handle an object that has been archived, but some of its reachable
1901 // objects cannot be archived. Bail out for now. We might need to fix this in the future if
1902 // we have a real use case.
1903 AOTMetaspace::unrecoverable_writing_error();
1904 }
1905 }
1906 }
1907
1908 Klass *orig_k = orig_obj->klass();
1909 subgraph_info->add_subgraph_object_klass(orig_k);
1910
1911 {
1912 // Find all the oops that are referenced by orig_obj, push them onto the stack
1913 // so we can work on them next.
1914 ResourceMark rm;
1915 OopFieldPusher pusher(stack, level, record_klasses_only, subgraph_info, orig_obj);
1916 orig_obj->oop_iterate(&pusher);
1917 }
1918
1919 if (CDSConfig::is_dumping_aot_linked_classes()) {
1920 // The enum klasses are archived with aot-initialized mirror.
1921 // See AOTClassInitializer::can_archive_initialized_mirror().
1922 } else {
1923 // This is legacy support for enum classes before JEP 483 -- we cannot rerun
1924 // the enum's <clinit> in the production run, so special handling is needed.
1925 if (CDSEnumKlass::is_enum_obj(orig_obj)) {
1926 CDSEnumKlass::handle_enum_obj(level + 1, subgraph_info, orig_obj);
1927 }
1928 }
1929
1930 return true;
1931 }
1932
1933 //
1934 // Start from the given static field in a java mirror and archive the
1935 // complete sub-graph of java heap objects that are reached directly
1936 // or indirectly from the starting object by following references.
1937 // Sub-graph archiving restrictions (current):
1938 //
1939 // - All classes of objects in the archived sub-graph (including the
1940 // entry class) must be boot class only.
1941 // - No java.lang.Class instance (java mirror) can be included inside
1942 // an archived sub-graph. Mirror can only be the sub-graph entry object.
1943 //
1944 // The Java heap object sub-graph archiving process (see OopFieldPusher):
1945 //
1946 // 1) Java object sub-graph archiving starts from a given static field
1947 // within a Class instance (java mirror). If the static field is a
1948 // reference field and points to a non-null java object, proceed to
1949 // the next step.
1950 //
1951 // 2) Archives the referenced java object. If an archived copy of the
1952 // current object already exists, updates the pointer in the archived
1953 // copy of the referencing object to point to the current archived object.
1954 // Otherwise, proceed to the next step.
1955 //
1956 // 3) Follows all references within the current java object and recursively
1957 // archive the sub-graph of objects starting from each reference.
1958 //
1959 // 4) Updates the pointer in the archived copy of referencing object to
1960 // point to the current archived object.
1961 //
1962 // 5) The Klass of the current java object is added to the list of Klasses
1963 // for loading and initializing before any object in the archived graph can
1964 // be accessed at runtime.
1965 //
1966 void HeapShared::archive_reachable_objects_from_static_field(InstanceKlass *k,
1967 const char* klass_name,
1968 int field_offset,
1969 const char* field_name) {
1970 precond(CDSConfig::is_dumping_klass_subgraphs());
1971 assert(k->defined_by_boot_loader(), "must be boot class");
1972
1973 oop m = k->java_mirror();
1974
1975 KlassSubGraphInfo* subgraph_info = get_subgraph_info(k);
1976 oop f = m->obj_field(field_offset);
1977
1978 log_debug(aot, heap)("Start archiving from: %s::%s (" PTR_FORMAT ")", klass_name, field_name, p2i(f));
1979
1980 if (!CompressedOops::is_null(f)) {
1981 if (log_is_enabled(Trace, aot, heap)) {
1982 LogTarget(Trace, aot, heap) log;
1983 LogStream out(log);
1984 f->print_on(&out);
1985 }
1986
1987 bool success = archive_reachable_objects_from(1, subgraph_info, f);
1988 if (!success) {
1989 log_error(aot, heap)("Archiving failed %s::%s (some reachable objects cannot be archived)",
1990 klass_name, field_name);
1991 } else {
1992 // Note: the field value is not preserved in the archived mirror.
1993 // Record the field as a new subGraph entry point. The recorded
1994 // information is restored from the archive at runtime.
1995 subgraph_info->add_subgraph_entry_field(field_offset, f);
1996 log_info(aot, heap)("Archived field %s::%s => " PTR_FORMAT, klass_name, field_name, p2i(f));
1997 }
1998 } else {
1999 // The field contains null, we still need to record the entry point,
2000 // so it can be restored at runtime.
2001 subgraph_info->add_subgraph_entry_field(field_offset, nullptr);
2002 }
2003 }
2004
2005 #ifndef PRODUCT
2006 class VerifySharedOopClosure: public BasicOopIterateClosure {
2007 public:
2008 void do_oop(narrowOop *p) { VerifySharedOopClosure::do_oop_work(p); }
2009 void do_oop( oop *p) { VerifySharedOopClosure::do_oop_work(p); }
2010
2011 protected:
2012 template <class T> void do_oop_work(T *p) {
2013 oop obj = HeapAccess<>::oop_load(p);
2014 if (obj != nullptr) {
2015 HeapShared::verify_reachable_objects_from(obj);
2016 }
2017 }
2018 };
2019
2020 void HeapShared::verify_subgraph_from_static_field(InstanceKlass* k, int field_offset) {
2021 precond(CDSConfig::is_dumping_klass_subgraphs());
2022 assert(k->defined_by_boot_loader(), "must be boot class");
2023
2024 oop m = k->java_mirror();
2025 oop f = m->obj_field(field_offset);
2026 if (!CompressedOops::is_null(f)) {
2027 verify_subgraph_from(f);
2028 }
2029 }
2030
2031 void HeapShared::verify_subgraph_from(oop orig_obj) {
2032 if (!has_been_archived(orig_obj)) {
2033 // It's OK for the root of a subgraph to be not archived. See comments in
2034 // archive_reachable_objects_from().
2035 return;
2036 }
2037
2038 // Verify that all objects reachable from orig_obj are archived.
2039 init_seen_objects_table();
2040 verify_reachable_objects_from(orig_obj);
2041 delete_seen_objects_table();
2042 }
2043
2044 void HeapShared::verify_reachable_objects_from(oop obj) {
2045 _num_total_verifications ++;
2046 if (java_lang_Class::is_instance(obj)) {
2047 Klass* k = java_lang_Class::as_Klass(obj);
2048 if (RegeneratedClasses::has_been_regenerated(k)) {
2049 k = RegeneratedClasses::get_regenerated_object(k);
2050 obj = k->java_mirror();
2051 }
2052 obj = scratch_java_mirror(obj);
2053 assert(obj != nullptr, "must be");
2054 }
2055 if (!has_been_seen_during_subgraph_recording(obj)) {
2056 set_has_been_seen_during_subgraph_recording(obj);
2057 assert(has_been_archived(obj), "must be");
2058 VerifySharedOopClosure walker;
2059 obj->oop_iterate(&walker);
2060 }
2061 }
2062 #endif
2063
2064 void HeapShared::check_special_subgraph_classes() {
2065 if (CDSConfig::is_dumping_aot_linked_classes()) {
2066 // We can have aot-initialized classes (such as Enums) that can reference objects
2067 // of arbitrary types. Currently, we trust the JEP 483 implementation to only
2068 // aot-initialize classes that are "safe".
2069 //
2070 // TODO: we need an automatic tool that checks the safety of aot-initialized
2071 // classes (when we extend the set of aot-initialized classes beyond JEP 483)
2072 return;
2073 } else {
2074 // In this case, the special subgraph should contain a few specific types
2075 GrowableArray<Klass*>* klasses = _dump_time_special_subgraph->subgraph_object_klasses();
2076 int num = klasses->length();
2077 for (int i = 0; i < num; i++) {
2078 Klass* subgraph_k = klasses->at(i);
2079 Symbol* name = subgraph_k->name();
2080 if (subgraph_k->is_instance_klass() &&
2081 name != vmSymbols::java_lang_Class() &&
2082 name != vmSymbols::java_lang_String() &&
2083 name != vmSymbols::java_lang_ArithmeticException() &&
2084 name != vmSymbols::java_lang_ArrayIndexOutOfBoundsException() &&
2085 name != vmSymbols::java_lang_ArrayStoreException() &&
2086 name != vmSymbols::java_lang_ClassCastException() &&
2087 name != vmSymbols::java_lang_InternalError() &&
2088 name != vmSymbols::java_lang_NullPointerException() &&
2089 name != vmSymbols::jdk_internal_vm_PreemptedException()) {
2090 ResourceMark rm;
2091 fatal("special subgraph cannot have objects of type %s", subgraph_k->external_name());
2092 }
2093 }
2094 }
2095 }
2096
2097 HeapShared::SeenObjectsTable* HeapShared::_seen_objects_table = nullptr;
2098 HeapShared::PendingOop HeapShared::_object_being_archived;
2099 size_t HeapShared::_num_new_walked_objs;
2100 size_t HeapShared::_num_new_archived_objs;
2101 size_t HeapShared::_num_old_recorded_klasses;
2102
2103 size_t HeapShared::_num_total_subgraph_recordings = 0;
2104 size_t HeapShared::_num_total_walked_objs = 0;
2105 size_t HeapShared::_num_total_archived_objs = 0;
2106 size_t HeapShared::_num_total_recorded_klasses = 0;
2107 size_t HeapShared::_num_total_verifications = 0;
2108
2109 bool HeapShared::has_been_seen_during_subgraph_recording(oop obj) {
2110 return _seen_objects_table->get(obj) != nullptr;
2111 }
2112
2113 void HeapShared::set_has_been_seen_during_subgraph_recording(oop obj) {
2114 assert(!has_been_seen_during_subgraph_recording(obj), "sanity");
2115 _seen_objects_table->put_when_absent(obj, true);
2116 _seen_objects_table->maybe_grow();
2117 ++ _num_new_walked_objs;
2118 }
2119
2120 void HeapShared::start_recording_subgraph(InstanceKlass *k, const char* class_name, bool is_full_module_graph) {
2121 log_info(aot, heap)("Start recording subgraph(s) for archived fields in %s", class_name);
2122 init_subgraph_info(k, is_full_module_graph);
2123 init_seen_objects_table();
2124 _num_new_walked_objs = 0;
2125 _num_new_archived_objs = 0;
2126 _num_old_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses();
2127 }
2128
2129 void HeapShared::done_recording_subgraph(InstanceKlass *k, const char* class_name) {
2130 size_t num_new_recorded_klasses = get_subgraph_info(k)->num_subgraph_object_klasses() -
2131 _num_old_recorded_klasses;
2132 log_info(aot, heap)("Done recording subgraph(s) for archived fields in %s: "
2133 "walked %zu objs, archived %zu new objs, recorded %zu classes",
2134 class_name, _num_new_walked_objs, _num_new_archived_objs,
2135 num_new_recorded_klasses);
2136
2137 delete_seen_objects_table();
2138
2139 _num_total_subgraph_recordings ++;
2140 _num_total_walked_objs += _num_new_walked_objs;
2141 _num_total_archived_objs += _num_new_archived_objs;
2142 _num_total_recorded_klasses += num_new_recorded_klasses;
2143 }
2144
2145 class ArchivableStaticFieldFinder: public FieldClosure {
2146 InstanceKlass* _ik;
2147 Symbol* _field_name;
2148 bool _found;
2149 int _offset;
2150 public:
2151 ArchivableStaticFieldFinder(InstanceKlass* ik, Symbol* field_name) :
2152 _ik(ik), _field_name(field_name), _found(false), _offset(-1) {}
2153
2154 virtual void do_field(fieldDescriptor* fd) {
2155 if (fd->name() == _field_name) {
2156 assert(!_found, "fields can never be overloaded");
2157 if (is_reference_type(fd->field_type())) {
2158 _found = true;
2159 _offset = fd->offset();
2160 }
2161 }
2162 }
2163 bool found() { return _found; }
2164 int offset() { return _offset; }
2165 };
2166
2167 void HeapShared::init_subgraph_entry_fields(ArchivableStaticFieldInfo fields[],
2168 TRAPS) {
2169 for (int i = 0; fields[i].valid(); i++) {
2170 ArchivableStaticFieldInfo* info = &fields[i];
2171 TempNewSymbol klass_name = SymbolTable::new_symbol(info->klass_name);
2172 TempNewSymbol field_name = SymbolTable::new_symbol(info->field_name);
2173 ResourceMark rm; // for stringStream::as_string() etc.
2174
2175 #ifndef PRODUCT
2176 bool is_test_class = (ArchiveHeapTestClass != nullptr) && (strcmp(info->klass_name, ArchiveHeapTestClass) == 0);
2177 const char* test_class_name = ArchiveHeapTestClass;
2178 #else
2179 bool is_test_class = false;
2180 const char* test_class_name = ""; // avoid C++ printf checks warnings.
2181 #endif
2182
2183 if (is_test_class) {
2184 log_warning(aot)("Loading ArchiveHeapTestClass %s ...", test_class_name);
2185 }
2186
2187 Klass* k = SystemDictionary::resolve_or_fail(klass_name, true, THREAD);
2188 if (HAS_PENDING_EXCEPTION) {
2189 CLEAR_PENDING_EXCEPTION;
2190 stringStream st;
2191 st.print("Fail to initialize archive heap: %s cannot be loaded by the boot loader", info->klass_name);
2192 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2193 }
2194
2195 if (!k->is_instance_klass()) {
2196 stringStream st;
2197 st.print("Fail to initialize archive heap: %s is not an instance class", info->klass_name);
2198 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2199 }
2200
2201 InstanceKlass* ik = InstanceKlass::cast(k);
2202 assert(InstanceKlass::cast(ik)->defined_by_boot_loader(),
2203 "Only support boot classes");
2204
2205 if (is_test_class) {
2206 if (ik->module()->is_named()) {
2207 // We don't want ArchiveHeapTestClass to be abused to easily load/initialize arbitrary
2208 // core-lib classes. You need to at least append to the bootclasspath.
2209 stringStream st;
2210 st.print("ArchiveHeapTestClass %s is not in unnamed module", test_class_name);
2211 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2212 }
2213
2214 if (ik->package() != nullptr) {
2215 // This restriction makes HeapShared::is_a_test_class_in_unnamed_module() easy.
2216 stringStream st;
2217 st.print("ArchiveHeapTestClass %s is not in unnamed package", test_class_name);
2218 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2219 }
2220 } else {
2221 if (ik->module()->name() != vmSymbols::java_base()) {
2222 // We don't want to deal with cases when a module is unavailable at runtime.
2223 // FUTURE -- load from archived heap only when module graph has not changed
2224 // between dump and runtime.
2225 stringStream st;
2226 st.print("%s is not in java.base module", info->klass_name);
2227 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2228 }
2229 }
2230
2231 if (is_test_class) {
2232 log_warning(aot)("Initializing ArchiveHeapTestClass %s ...", test_class_name);
2233 }
2234 ik->initialize(CHECK);
2235
2236 ArchivableStaticFieldFinder finder(ik, field_name);
2237 ik->do_local_static_fields(&finder);
2238 if (!finder.found()) {
2239 stringStream st;
2240 st.print("Unable to find the static T_OBJECT field %s::%s", info->klass_name, info->field_name);
2241 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(), st.as_string());
2242 }
2243
2244 info->klass = ik;
2245 info->offset = finder.offset();
2246 }
2247 }
2248
2249 void HeapShared::init_subgraph_entry_fields(TRAPS) {
2250 assert(CDSConfig::is_dumping_heap(), "must be");
2251 _dump_time_subgraph_info_table = new (mtClass)DumpTimeKlassSubGraphInfoTable();
2252 if (CDSConfig::is_dumping_klass_subgraphs()) {
2253 init_subgraph_entry_fields(archive_subgraph_entry_fields, CHECK);
2254 if (CDSConfig::is_dumping_full_module_graph()) {
2255 init_subgraph_entry_fields(fmg_archive_subgraph_entry_fields, CHECK);
2256 }
2257 }
2258 }
2259
2260 #ifndef PRODUCT
2261 void HeapShared::setup_test_class(const char* test_class_name) {
2262 ArchivableStaticFieldInfo* p = archive_subgraph_entry_fields;
2263 int num_slots = sizeof(archive_subgraph_entry_fields) / sizeof(ArchivableStaticFieldInfo);
2264 assert(p[num_slots - 2].klass_name == nullptr, "must have empty slot that's patched below");
2265 assert(p[num_slots - 1].klass_name == nullptr, "must have empty slot that marks the end of the list");
2266
2267 if (test_class_name != nullptr) {
2268 p[num_slots - 2].klass_name = test_class_name;
2269 p[num_slots - 2].field_name = ARCHIVE_TEST_FIELD_NAME;
2270 }
2271 }
2272
2273 // See if ik is one of the test classes that are pulled in by -XX:ArchiveHeapTestClass
2274 // during runtime. This may be called before the module system is initialized so
2275 // we cannot rely on InstanceKlass::module(), etc.
2276 bool HeapShared::is_a_test_class_in_unnamed_module(Klass* ik) {
2277 if (_test_class != nullptr) {
2278 if (ik == _test_class) {
2279 return true;
2280 }
2281 Array<Klass*>* klasses = _test_class_record->subgraph_object_klasses();
2282 if (klasses == nullptr) {
2283 return false;
2284 }
2285
2286 for (int i = 0; i < klasses->length(); i++) {
2287 Klass* k = klasses->at(i);
2288 if (k == ik) {
2289 Symbol* name;
2290 if (k->is_instance_klass()) {
2291 name = InstanceKlass::cast(k)->name();
2292 } else if (k->is_objArray_klass()) {
2293 Klass* bk = ObjArrayKlass::cast(k)->bottom_klass();
2294 if (!bk->is_instance_klass()) {
2295 return false;
2296 }
2297 name = bk->name();
2298 } else {
2299 return false;
2300 }
2301
2302 // See KlassSubGraphInfo::check_allowed_klass() - we only allow test classes
2303 // to be:
2304 // (A) java.base classes (which must not be in the unnamed module)
2305 // (B) test classes which must be in the unnamed package of the unnamed module.
2306 // So if we see a '/' character in the class name, it must be in (A);
2307 // otherwise it must be in (B).
2308 if (name->index_of_at(0, "/", 1) >= 0) {
2309 return false; // (A)
2310 }
2311
2312 return true; // (B)
2313 }
2314 }
2315 }
2316
2317 return false;
2318 }
2319
2320 void HeapShared::initialize_test_class_from_archive(JavaThread* current) {
2321 Klass* k = _test_class;
2322 if (k != nullptr && is_archived_heap_in_use()) {
2323 JavaThread* THREAD = current;
2324 ExceptionMark em(THREAD);
2325 const ArchivedKlassSubGraphInfoRecord* record =
2326 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/false, THREAD);
2327
2328 // The _test_class is in the unnamed module, so it can't call CDS.initializeFromArchive()
2329 // from its <clinit> method. So we set up its "archivedObjects" field first, before
2330 // calling its <clinit>. This is not strictly clean, but it's a convenient way to write unit
2331 // test cases (see test/hotspot/jtreg/runtime/cds/appcds/cacheObject/ArchiveHeapTestClass.java).
2332 if (record != nullptr) {
2333 init_archived_fields_for(k, record);
2334 }
2335 resolve_or_init_classes_for_subgraph_of(k, /*do_init=*/true, THREAD);
2336 }
2337 }
2338 #endif
2339
2340 void HeapShared::init_for_dumping(TRAPS) {
2341 if (CDSConfig::is_dumping_heap()) {
2342 setup_test_class(ArchiveHeapTestClass);
2343 init_subgraph_entry_fields(CHECK);
2344 }
2345 }
2346
2347 void HeapShared::init_heap_writer() {
2348 if (HeapShared::is_writing_streaming_mode()) {
2349 AOTStreamedHeapWriter::init();
2350 } else {
2351 AOTMappedHeapWriter::init();
2352 }
2353 }
2354
2355 void HeapShared::archive_object_subgraphs(ArchivableStaticFieldInfo fields[],
2356 bool is_full_module_graph) {
2357 _num_total_subgraph_recordings = 0;
2358 _num_total_walked_objs = 0;
2359 _num_total_archived_objs = 0;
2360 _num_total_recorded_klasses = 0;
2361 _num_total_verifications = 0;
2362
2363 // For each class X that has one or more archived fields:
2364 // [1] Dump the subgraph of each archived field
2365 // [2] Create a list of all the class of the objects that can be reached
2366 // by any of these static fields.
2367 // At runtime, these classes are initialized before X's archived fields
2368 // are restored by HeapShared::initialize_from_archived_subgraph().
2369 for (int i = 0; fields[i].valid(); ) {
2370 ArchivableStaticFieldInfo* info = &fields[i];
2371 const char* klass_name = info->klass_name;
2372 start_recording_subgraph(info->klass, klass_name, is_full_module_graph);
2373
2374 // If you have specified consecutive fields of the same klass in
2375 // fields[], these will be archived in the same
2376 // {start_recording_subgraph ... done_recording_subgraph} pass to
2377 // save time.
2378 for (; fields[i].valid(); i++) {
2379 ArchivableStaticFieldInfo* f = &fields[i];
2380 if (f->klass_name != klass_name) {
2381 break;
2382 }
2383
2384 archive_reachable_objects_from_static_field(f->klass, f->klass_name,
2385 f->offset, f->field_name);
2386 }
2387 done_recording_subgraph(info->klass, klass_name);
2388 }
2389
2390 log_info(aot, heap)("Archived subgraph records = %zu",
2391 _num_total_subgraph_recordings);
2392 log_info(aot, heap)(" Walked %zu objects", _num_total_walked_objs);
2393 log_info(aot, heap)(" Archived %zu objects", _num_total_archived_objs);
2394 log_info(aot, heap)(" Recorded %zu klasses", _num_total_recorded_klasses);
2395
2396 #ifndef PRODUCT
2397 for (int i = 0; fields[i].valid(); i++) {
2398 ArchivableStaticFieldInfo* f = &fields[i];
2399 verify_subgraph_from_static_field(f->klass, f->offset);
2400 }
2401 log_info(aot, heap)(" Verified %zu references", _num_total_verifications);
2402 #endif
2403 }
2404
2405 bool HeapShared::is_interned_string(oop obj) {
2406 if (!java_lang_String::is_instance(obj)) {
2407 return false;
2408 }
2409
2410 ResourceMark rm;
2411 int len = 0;
2412 jchar* name = java_lang_String::as_unicode_string_or_null(obj, len);
2413 if (name == nullptr) {
2414 fatal("Insufficient memory for dumping");
2415 }
2416 return StringTable::lookup(name, len) == obj;
2417 }
2418
2419 bool HeapShared::is_dumped_interned_string(oop o) {
2420 return is_interned_string(o) && has_been_archived(o);
2421 }
2422
2423 // These tables should be used only within the CDS safepoint, so
2424 // delete them before we exit the safepoint. Otherwise the table will
2425 // contain bad oops after a GC.
2426 void HeapShared::delete_tables_with_raw_oops() {
2427 assert(_seen_objects_table == nullptr, "should have been deleted");
2428
2429 if (is_writing_mapping_mode()) {
2430 AOTMappedHeapWriter::delete_tables_with_raw_oops();
2431 } else {
2432 assert(is_writing_streaming_mode(), "what other mode?");
2433 AOTStreamedHeapWriter::delete_tables_with_raw_oops();
2434 }
2435 }
2436
2437 void HeapShared::debug_trace() {
2438 ResourceMark rm;
2439 oop referrer = _object_being_archived.referrer();
2440 if (referrer != nullptr) {
2441 LogStream ls(Log(aot, heap)::error());
2442 ls.print_cr("Reference trace");
2443 CDSHeapVerifier::trace_to_root(&ls, referrer);
2444 }
2445 }
2446
2447 #ifndef PRODUCT
2448 // At dump-time, find the location of all the non-null oop pointers in an archived heap
2449 // region. This way we can quickly relocate all the pointers without using
2450 // BasicOopIterateClosure at runtime.
2451 class FindEmbeddedNonNullPointers: public BasicOopIterateClosure {
2452 void* _start;
2453 BitMap *_oopmap;
2454 size_t _num_total_oops;
2455 size_t _num_null_oops;
2456 public:
2457 FindEmbeddedNonNullPointers(void* start, BitMap* oopmap)
2458 : _start(start), _oopmap(oopmap), _num_total_oops(0), _num_null_oops(0) {}
2459
2460 virtual void do_oop(narrowOop* p) {
2461 assert(UseCompressedOops, "sanity");
2462 _num_total_oops ++;
2463 narrowOop v = *p;
2464 if (!CompressedOops::is_null(v)) {
2465 size_t idx = p - (narrowOop*)_start;
2466 _oopmap->set_bit(idx);
2467 } else {
2468 _num_null_oops ++;
2469 }
2470 }
2471 virtual void do_oop(oop* p) {
2472 assert(!UseCompressedOops, "sanity");
2473 _num_total_oops ++;
2474 if ((*p) != nullptr) {
2475 size_t idx = p - (oop*)_start;
2476 _oopmap->set_bit(idx);
2477 } else {
2478 _num_null_oops ++;
2479 }
2480 }
2481 size_t num_total_oops() const { return _num_total_oops; }
2482 size_t num_null_oops() const { return _num_null_oops; }
2483 };
2484 #endif
2485
2486 void HeapShared::count_allocation(size_t size) {
2487 _total_obj_count ++;
2488 _total_obj_size += size;
2489 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
2490 if (size <= (size_t(1) << i)) {
2491 _alloc_count[i] ++;
2492 _alloc_size[i] += size;
2493 return;
2494 }
2495 }
2496 }
2497
2498 static double avg_size(size_t size, size_t count) {
2499 double avg = 0;
2500 if (count > 0) {
2501 avg = double(size * HeapWordSize) / double(count);
2502 }
2503 return avg;
2504 }
2505
2506 void HeapShared::print_stats() {
2507 size_t huge_count = _total_obj_count;
2508 size_t huge_size = _total_obj_size;
2509
2510 for (int i = 0; i < ALLOC_STAT_SLOTS; i++) {
2511 size_t byte_size_limit = (size_t(1) << i) * HeapWordSize;
2512 size_t count = _alloc_count[i];
2513 size_t size = _alloc_size[i];
2514 log_info(aot, heap)("%8zu objects are <= %-6zu"
2515 " bytes (total %8zu bytes, avg %8.1f bytes)",
2516 count, byte_size_limit, size * HeapWordSize, avg_size(size, count));
2517 huge_count -= count;
2518 huge_size -= size;
2519 }
2520
2521 log_info(aot, heap)("%8zu huge objects (total %8zu bytes"
2522 ", avg %8.1f bytes)",
2523 huge_count, huge_size * HeapWordSize,
2524 avg_size(huge_size, huge_count));
2525 log_info(aot, heap)("%8zu total objects (total %8zu bytes"
2526 ", avg %8.1f bytes)",
2527 _total_obj_count, _total_obj_size * HeapWordSize,
2528 avg_size(_total_obj_size, _total_obj_count));
2529 }
2530
2531 bool HeapShared::is_metadata_field(oop src_obj, int offset) {
2532 bool result = false;
2533 do_metadata_offsets(src_obj, [&](int metadata_offset) {
2534 if (metadata_offset == offset) {
2535 result = true;
2536 }
2537 });
2538 return result;
2539 }
2540
2541 void HeapShared::remap_dumped_metadata(oop src_obj, address archived_object) {
2542 do_metadata_offsets(src_obj, [&](int offset) {
2543 Metadata** buffered_field_addr = (Metadata**)(archived_object + offset);
2544 Metadata* native_ptr = *buffered_field_addr;
2545
2546 if (native_ptr == nullptr) {
2547 return;
2548 }
2549
2550 if (RegeneratedClasses::has_been_regenerated(native_ptr)) {
2551 native_ptr = RegeneratedClasses::get_regenerated_object(native_ptr);
2552 }
2553
2554 address buffered_native_ptr = ArchiveBuilder::current()->get_buffered_addr((address)native_ptr);
2555 address requested_native_ptr = ArchiveBuilder::current()->to_requested(buffered_native_ptr);
2556 *buffered_field_addr = (Metadata*)requested_native_ptr;
2557 });
2558 }
2559
2560 bool HeapShared::is_archived_boot_layer_available(JavaThread* current) {
2561 TempNewSymbol klass_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_CLASS);
2562 InstanceKlass* k = SystemDictionary::find_instance_klass(current, klass_name, Handle());
2563 if (k == nullptr) {
2564 return false;
2565 } else {
2566 TempNewSymbol field_name = SymbolTable::new_symbol(ARCHIVED_BOOT_LAYER_FIELD);
2567 TempNewSymbol field_signature = SymbolTable::new_symbol("Ljdk/internal/module/ArchivedBootLayer;");
2568 fieldDescriptor fd;
2569 if (k->find_field(field_name, field_signature, true, &fd) != nullptr) {
2570 oop m = k->java_mirror();
2571 oop f = m->obj_field(fd.offset());
2572 if (CompressedOops::is_null(f)) {
2573 return false;
2574 }
2575 } else {
2576 return false;
2577 }
2578 }
2579 return true;
2580 }
2581
2582 #endif // INCLUDE_CDS_JAVA_HEAP